diff --git a/src/main/java/org/datadog/jmxfetch/App.java b/src/main/java/org/datadog/jmxfetch/App.java
index a11a67a9b..fd0a60cab 100644
--- a/src/main/java/org/datadog/jmxfetch/App.java
+++ b/src/main/java/org/datadog/jmxfetch/App.java
@@ -35,7 +35,6 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Map;
@@ -77,7 +76,7 @@ public class App {
     private ConcurrentHashMap<String, YamlParser> configs;
     private ConcurrentHashMap<String, YamlParser> adPipeConfigs =
             new ConcurrentHashMap<String, YamlParser>();
-    private ArrayList<Instance> instances = new ArrayList<Instance>();
+    private List<Instance> instances = new ArrayList<Instance>();
     private Map<String, Instance> brokenInstanceMap = new ConcurrentHashMap<String, Instance>();
     private AtomicBoolean reinit = new AtomicBoolean(false);
 
@@ -255,12 +254,9 @@ public static int getLoopCounter() {
     }
 
     private void clearInstances(Collection<Instance> instances) {
-        List<InstanceTask<Void>> cleanupInstanceTasks = new ArrayList<InstanceTask<Void>>();
-
-        Iterator<Instance> iterator = instances.iterator();
-        while (iterator.hasNext()) {
-            Instance instance = iterator.next();
-
+        List<InstanceTask<Void>> cleanupInstanceTasks =
+                new ArrayList<InstanceTask<Void>>(instances.size());
+        for (Instance instance : instances) {
             // create the cleanup task
             cleanupInstanceTasks.add(new InstanceCleanupTask(instance));
         }
@@ -375,7 +371,7 @@ public boolean processAutoDiscovery(byte[] buffer) {
         return reinit;
     }
 
-    protected ArrayList<Instance> getInstances() {
+    protected List<Instance> getInstances() {
         return this.instances;
     }
 
@@ -494,8 +490,8 @@ public void doIteration() {
         loopCounter++;
 
         try {
-            List<InstanceTask<LinkedList<HashMap<String, Object>>>> getMetricsTasks =
-                    new ArrayList<InstanceTask<LinkedList<HashMap<String, Object>>>>();
+            List<InstanceTask<List<HashMap<String, Object>>>> getMetricsTasks =
+                    new ArrayList<InstanceTask<List<HashMap<String, Object>>>>(instances.size());
 
             for (Instance instance : instances) {
                 getMetricsTasks.add(new MetricCollectionTask(instance));
@@ -515,11 +511,11 @@ public void doIteration() {
                             getMetricsTasks,
                             appConfig.getCollectionTimeout(),
                             TimeUnit.SECONDS,
-                            new TaskMethod<LinkedList<HashMap<String, Object>>>() {
+                            new TaskMethod<List<HashMap<String, Object>>>() {
                                 @Override
                                 public TaskStatusHandler invoke(
                                         Instance instance,
-                                        Future<LinkedList<HashMap<String, Object>>> future,
+                                        Future<List<HashMap<String, Object>>> future,
                                         Reporter reporter) {
                                     return App.processCollectionResults(instance, future, reporter);
                                 }
@@ -560,7 +556,8 @@ public TaskStatusHandler invoke(
     }
 
     private void fixBrokenInstances(Reporter reporter) {
-        List<InstanceTask<Void>> fixInstanceTasks = new ArrayList<InstanceTask<Void>>();
+        List<InstanceTask<Void>> fixInstanceTasks =
+                new ArrayList<InstanceTask<Void>>(brokenInstanceMap.values().size());
 
         for (Instance instance : brokenInstanceMap.values()) {
             // Clearing rates aggregator so we won't compute wrong rates if we can reconnect
@@ -835,7 +832,6 @@ public void init(boolean forceNewConnection) {
         clearInstances(brokenInstanceMap.values());
         brokenInstanceMap.clear();
 
-        List<InstanceTask<Void>> instanceInitTasks = new ArrayList<InstanceTask<Void>>();
         List<Instance> newInstances = new ArrayList<Instance>();
 
         log.info("Dealing with YAML config instances...");
@@ -858,8 +854,8 @@ public void init(boolean forceNewConnection) {
                 it.remove();
             }
 
-            ArrayList<Map<String, Object>> configInstances =
-                    ((ArrayList<Map<String, Object>>) yamlConfig.getYamlInstances());
+            List<Map<String, Object>> configInstances =
+                    ((List<Map<String, Object>>) yamlConfig.getYamlInstances());
             if (configInstances == null || configInstances.size() == 0) {
                 String warning = "No instance found in :" + name;
                 log.warn(warning);
@@ -896,8 +892,8 @@ public void init(boolean forceNewConnection) {
                         (HashMap<String, Object>) adJsonConfigs.get(check);
                 Map<String, Object> initConfig =
                         (Map<String, Object>) checkConfig.get("init_config");
-                ArrayList<Map<String, Object>> configInstances =
-                        (ArrayList<Map<String, Object>>) checkConfig.get("instances");
+                List<Map<String, Object>> configInstances =
+                        (List<Map<String, Object>>) checkConfig.get("instances");
                 String checkName = (String) checkConfig.get("check_name");
                 for (Map<String, Object> configInstance : configInstances) {
                     log.info("Instantiating instance for: " + checkName);
@@ -908,6 +904,8 @@ public void init(boolean forceNewConnection) {
             }
         }
 
+        List<InstanceTask<Void>> instanceInitTasks =
+                new ArrayList<InstanceTask<Void>>(newInstances.size());
         for (Instance instance : newInstances) {
             // create the initializing tasks
             instanceInitTasks.add(new InstanceInitializingTask(instance, forceNewConnection));
@@ -978,7 +976,7 @@ static TaskStatusHandler processRecoveryResults(
 
     static TaskStatusHandler processCollectionResults(
             Instance instance,
-            Future<LinkedList<HashMap<String, Object>>> future,
+            Future<List<HashMap<String, Object>>> future,
             Reporter reporter) {
 
         TaskStatusHandler status = new TaskStatusHandler();
@@ -988,7 +986,7 @@ static TaskStatusHandler processCollectionResults(
             int numberOfMetrics = 0;
 
             if (future.isDone()) {
-                LinkedList<HashMap<String, Object>> metrics;
+                List<HashMap<String, Object>> metrics;
                 metrics = future.get();
                 numberOfMetrics = metrics.size();
 
@@ -1125,7 +1123,7 @@ private <T> void processCollectionStatus(
             String instanceMessage = null;
             String instanceStatus = Status.STATUS_OK;
             String scStatus = Status.STATUS_OK;
-            LinkedList<HashMap<String, Object>> metrics;
+            List<HashMap<String, Object>> metrics;
 
             int numberOfMetrics = 0;
 
@@ -1138,7 +1136,7 @@ private <T> void processCollectionStatus(
                 status.raiseForStatus();
 
                 // If we get here all was good - metric count  available
-                metrics = (LinkedList<HashMap<String, Object>>) status.getData();
+                metrics = (List<HashMap<String, Object>>) status.getData();
                 numberOfMetrics = metrics.size();
 
                 if (instance.isLimitReached()) {
diff --git a/src/main/java/org/datadog/jmxfetch/Configuration.java b/src/main/java/org/datadog/jmxfetch/Configuration.java
index 5541af522..ee5da7cd4 100644
--- a/src/main/java/org/datadog/jmxfetch/Configuration.java
+++ b/src/main/java/org/datadog/jmxfetch/Configuration.java
@@ -4,7 +4,7 @@
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
-import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
@@ -52,10 +52,9 @@ private Boolean hasInclude() {
      * @param configurationList the configuration list to filter
      * @return a configuration list
      */
-    private static LinkedList<Configuration> getIncludeConfigurationList(
-            LinkedList<Configuration> configurationList) {
-        LinkedList<Configuration> includeConfigList =
-                new LinkedList<Configuration>(configurationList);
+    private static List<Configuration> getIncludeConfigurationList(
+            List<Configuration> configurationList) {
+        List<Configuration> includeConfigList = new ArrayList<Configuration>(configurationList);
         Iterator<Configuration> confItr = includeConfigList.iterator();
 
         while (confItr.hasNext()) {
@@ -73,18 +72,18 @@ private static LinkedList<Configuration> getIncludeConfigurationList(
      * @param configurationList the configuration list to process
      * @return filters by domain name
      */
-    private static HashMap<String, LinkedList<Filter>> getIncludeFiltersByDomain(
-            LinkedList<Configuration> configurationList) {
-        HashMap<String, LinkedList<Filter>> includeFiltersByDomain =
-                new HashMap<String, LinkedList<Filter>>();
+    private static HashMap<String, List<Filter>> getIncludeFiltersByDomain(
+            List<Configuration> configurationList) {
+        HashMap<String, List<Filter>> includeFiltersByDomain =
+                new HashMap<String, List<Filter>>();
 
         for (Configuration conf : configurationList) {
             Filter filter = conf.getInclude();
-            LinkedList<Filter> filters = new LinkedList<Filter>();
+            List<Filter> filters = new ArrayList<Filter>();
 
             // Convert bean name, to a proper filter, i.e. a hash
             if (!filter.isEmptyBeanName()) {
-                ArrayList<String> beanNames = filter.getBeanNames();
+                List<String> beanNames = filter.getBeanNames();
 
                 for (String beanName : beanNames) {
                     String[] splitBeanName = beanName.split(":");
@@ -101,13 +100,13 @@ private static HashMap<String, LinkedList<Filter>> getIncludeFiltersByDomain(
 
             for (Filter f : filters) {
                 //  Retrieve the existing filters for the domain, add the new filters
-                LinkedList<Filter> domainFilters;
+                List<Filter> domainFilters;
                 String domainName = f.getDomain();
 
                 if (includeFiltersByDomain.containsKey(domainName)) {
                     domainFilters = includeFiltersByDomain.get(domainName);
                 } else {
-                    domainFilters = new LinkedList<Filter>();
+                    domainFilters = new ArrayList<Filter>();
                 }
 
                 domainFilters.add(f);
@@ -124,16 +123,17 @@ private static HashMap<String, LinkedList<Filter>> getIncludeFiltersByDomain(
      * @return common bean key parameters by domain name
      */
     private static Map<String, Set<String>> getCommonBeanKeysByDomain(
-            Map<String, LinkedList<Filter>> filtersByDomain) {
+            Map<String, List<Filter>> filtersByDomain) {
         Map<String, Set<String>> beanKeysIntersectionByDomain =
                 new HashMap<String, Set<String>>();
 
-        for (Entry<String, LinkedList<Filter>> filtersEntry : filtersByDomain.entrySet()) {
-            String domainName = filtersEntry.getKey();
-            LinkedList<Filter> filters = filtersEntry.getValue();
-
+        for (Entry<String, List<Filter>> filtersEntry : filtersByDomain.entrySet()) {
+            List<Filter> filters = filtersEntry.getValue();
+            if (filters == null || filters.isEmpty()) {
+                continue;
+            }
             // Compute keys intersection
-            Set<String> keysIntersection = new HashSet<String>(filters.getFirst().keySet());
+            Set<String> keysIntersection = new HashSet<String>(filters.get(0).keySet());
 
             for (Filter filter : filters) {
                 keysIntersection.retainAll(filter.keySet());
@@ -143,7 +143,7 @@ private static Map<String, Set<String>> getCommonBeanKeysByDomain(
             for (String param : JmxAttribute.getExcludedBeanParams()) {
                 keysIntersection.remove(param);
             }
-
+            String domainName = filtersEntry.getKey();
             beanKeysIntersectionByDomain.put(domainName, keysIntersection);
         }
 
@@ -160,7 +160,7 @@ private static Map<String, Set<String>> getCommonBeanKeysByDomain(
      */
     private static Map<String, Map<String, String>> getCommonScopeByDomain(
             Map<String, Set<String>> beanKeysByDomain,
-            Map<String, LinkedList<Filter>> filtersByDomain) {
+            Map<String, List<Filter>> filtersByDomain) {
         // Compute a common scope a among filters by domain name
         Map<String, Map<String, String>> commonScopeByDomain =
                 new HashMap<String, Map<String, String>>();
@@ -169,16 +169,16 @@ private static Map<String, Map<String, String>> getCommonScopeByDomain(
                 beanKeysByDomain.entrySet()) {
             String domainName = commonParametersByDomainEntry.getKey();
             Set<String> commonParameters = commonParametersByDomainEntry.getValue();
-            LinkedList<Filter> filters = filtersByDomain.get(domainName);
+            List<Filter> filters = filtersByDomain.get(domainName);
             Map<String, String> commonScope = new HashMap<String, String>();
 
             for (String parameter : commonParameters) {
                 // Check if all values associated with the parameters are the same
                 String commonValue = null;
-                Boolean hasCommonValue = true;
+                boolean hasCommonValue = true;
 
                 for (Filter f : filters) {
-                    ArrayList<String> parameterValues = f.getParameterValues(parameter);
+                    List<String> parameterValues = f.getParameterValues(parameter);
 
                     if (parameterValues.size() != 1
                             || (commonValue != null
@@ -231,18 +231,18 @@ private static String beanScopeToString(
      * @param configurationList the configuration list to process
      * @return common bean pattern strings
      */
-    public static LinkedList<String> getGreatestCommonScopes(
-            LinkedList<Configuration> configurationList) {
-        LinkedList<Configuration> includeConfigList =
+    public static List<String> getGreatestCommonScopes(
+            List<Configuration> configurationList) {
+        List<Configuration> includeConfigList =
                 getIncludeConfigurationList(configurationList);
-        Map<String, LinkedList<Filter>> includeFiltersByDomain =
+        Map<String, List<Filter>> includeFiltersByDomain =
                 getIncludeFiltersByDomain(includeConfigList);
         Map<String, Set<String>> parametersIntersectionByDomain =
                 getCommonBeanKeysByDomain(includeFiltersByDomain);
         Map<String, Map<String, String>> commonBeanScopeByDomain =
                 getCommonScopeByDomain(parametersIntersectionByDomain, includeFiltersByDomain);
 
-        LinkedList<String> result = new LinkedList<String>();
+        List<String> result = new ArrayList<String>(commonBeanScopeByDomain.entrySet().size());
 
         for (Entry<String, Map<String, String>> beanScopeEntry :
                 commonBeanScopeByDomain.entrySet()) {
diff --git a/src/main/java/org/datadog/jmxfetch/Filter.java b/src/main/java/org/datadog/jmxfetch/Filter.java
index 40ffed831..cc214d47c 100644
--- a/src/main/java/org/datadog/jmxfetch/Filter.java
+++ b/src/main/java/org/datadog/jmxfetch/Filter.java
@@ -1,15 +1,18 @@
 package org.datadog.jmxfetch;
 
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Set;
 import java.util.regex.Pattern;
 
 class Filter {
     HashMap<String, Object> filter;
     Pattern domainRegex;
-    ArrayList<Pattern> beanRegexes = null;
-    ArrayList<String> excludeTags = null;
+    List<Pattern> beanRegexes = null;
+    List<String> excludeTags = null;
     HashMap<String, String> additionalTags = null;
 
     /**
@@ -37,8 +40,8 @@ public Set<String> keySet() {
         return filter.keySet();
     }
 
-    @SuppressWarnings({"unchecked", "serial"})
-    private static ArrayList<String> toStringArrayList(final Object toCast) {
+    @SuppressWarnings({"unchecked"})
+    private static List<String> toStringList(final Object toCast) {
         // Return object as an ArrayList wherever it's defined as
         // list or not
         //
@@ -49,20 +52,15 @@ private static ArrayList<String> toStringArrayList(final Object toCast) {
         // ### OR
         // object: singleValue
         // ###
-        try {
-            return (ArrayList<String>) toCast;
-        } catch (ClassCastException e) {
-            return new ArrayList<String>() {
-                {
-                    add(((String) toCast));
-                }
-            };
+        if (toCast instanceof List) {
+            return (List<String>) toCast;
         }
+        return new ArrayList<String>(Arrays.asList((String) toCast));
     }
 
-    public ArrayList<String> getBeanNames() {
+    public List<String> getBeanNames() {
         if (isEmptyBeanName()) {
-            return new ArrayList<String>();
+            return Collections.emptyList();
         }
         final Object beanNames =
                 (filter.get("bean") != null) ? filter.get("bean") : filter.get("bean_name");
@@ -77,44 +75,43 @@ public ArrayList<String> getBeanNames() {
         // ### OR
         // bean: org.datadog.jmxfetch.test:type=type=SimpleTestJavaApp
         // ###
-        return toStringArrayList(beanNames);
+        return toStringList(beanNames);
     }
 
-    private static ArrayList<Pattern> toPatternArrayList(final Object toCast) {
-        ArrayList<Pattern> patternArrayList = new ArrayList<Pattern>();
-        ArrayList<String> stringArrayList = toStringArrayList(toCast);
-        for (String string : stringArrayList) {
-            patternArrayList.add(Pattern.compile(string));
+    private static List<Pattern> toPatternList(final Object toCast) {
+        List<Pattern> patternList = new ArrayList<Pattern>();
+        List<String> stringList = toStringList(toCast);
+        for (String string : stringList) {
+            patternList.add(Pattern.compile(string));
         }
-
-        return patternArrayList;
+        return patternList;
     }
 
-    public ArrayList<Pattern> getBeanRegexes() {
+    public List<Pattern> getBeanRegexes() {
         // Return bean regexes as an ArrayList of Pattern whether it's defined as
         // a list or not
 
         if (this.beanRegexes == null) {
             if (filter.get("bean_regex") == null) {
-                this.beanRegexes = new ArrayList<Pattern>();
+                this.beanRegexes = Collections.emptyList();
             } else {
                 final Object beanRegexNames = filter.get("bean_regex");
-                this.beanRegexes = toPatternArrayList(beanRegexNames);
+                this.beanRegexes = toPatternList(beanRegexNames);
             }
         }
 
         return this.beanRegexes;
     }
 
-    public ArrayList<String> getExcludeTags() {
+    public List<String> getExcludeTags() {
         // Return excluded tags  as an ArrayList whether it's defined as a list or not
 
         if (this.excludeTags == null) {
             if (filter.get("exclude_tags") == null) {
-                this.excludeTags = new ArrayList<String>();
+                this.excludeTags = Collections.emptyList();
             } else {
                 final Object exclude_tags = filter.get("exclude_tags");
-                this.excludeTags = toStringArrayList(exclude_tags);
+                this.excludeTags = toStringList(exclude_tags);
             }
         }
 
@@ -154,7 +151,7 @@ public Object getAttribute() {
         return filter.get("attribute");
     }
 
-    public ArrayList<String> getParameterValues(String parameterName) {
+    public List<String> getParameterValues(String parameterName) {
         // Return bean attributes values as an ArrayList wherever it's defined as
         // list or not
         //
@@ -166,7 +163,7 @@ public ArrayList<String> getParameterValues(String parameterName) {
         // bean_parameter: onlyOneType
         // ###
         final Object beanValues = filter.get(parameterName);
-        return toStringArrayList(beanValues);
+        return toStringList(beanValues);
     }
 
     public boolean isEmptyBeanName() {
diff --git a/src/main/java/org/datadog/jmxfetch/Instance.java b/src/main/java/org/datadog/jmxfetch/Instance.java
index ac5f8cebb..ec8069b00 100644
--- a/src/main/java/org/datadog/jmxfetch/Instance.java
+++ b/src/main/java/org/datadog/jmxfetch/Instance.java
@@ -16,7 +16,6 @@
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -77,9 +76,9 @@ public Yaml initialValue() {
         };
 
     private Set<ObjectName> beans;
-    private LinkedList<String> beanScopes;
-    private LinkedList<Configuration> configurationList = new LinkedList<Configuration>();
-    private LinkedList<JmxAttribute> matchingAttributes;
+    private List<String> beanScopes;
+    private List<Configuration> configurationList = new ArrayList<Configuration>();
+    private List<JmxAttribute> matchingAttributes;
     private HashSet<JmxAttribute> failingAttributes;
     private Integer refreshBeansPeriod;
     private long lastCollectionTime;
@@ -124,7 +123,7 @@ public Instance(
         this.instanceName = (String) instanceMap.get("name");
         this.tags = getTagsMap(instanceMap.get("tags"), appConfig);
         this.checkName = checkName;
-        this.matchingAttributes = new LinkedList<JmxAttribute>();
+        this.matchingAttributes = new ArrayList<JmxAttribute>();
         this.failingAttributes = new HashSet<JmxAttribute>();
         if (appConfig.getRefreshBeansPeriod() == null) {
             this.refreshBeansPeriod = (Integer) instanceMap.get("refresh_beans");
@@ -196,7 +195,7 @@ public Instance(
             log.warn("Cannot find a \"conf\" section in " + this.instanceName);
         } else {
             for (Map<String, Object> conf :
-                    (ArrayList<Map<String, Object>>) (instanceConf)) {
+                    (List<Map<String, Object>>) (instanceConf)) {
                 configurationList.add(new Configuration(conf));
             }
         }
@@ -223,8 +222,8 @@ public static boolean isDirectInstance(Map<String, Object> configInstance) {
     }
 
     private void loadDefaultConfig(String configResourcePath) {
-        ArrayList<Map<String, Object>> defaultConf =
-                (ArrayList<Map<String, Object>>)
+        List<Map<String, Object>> defaultConf =
+                (List<Map<String, Object>>)
                         YAML.get().load(this.getClass().getResourceAsStream(configResourcePath));
         for (Map<String, Object> conf : defaultConf) {
             configurationList.add(new Configuration(conf));
@@ -233,7 +232,7 @@ private void loadDefaultConfig(String configResourcePath) {
 
     @VisibleForTesting
     static void loadMetricConfigFiles(
-            AppConfig appConfig, LinkedList<Configuration> configurationList) {
+            AppConfig appConfig, List<Configuration> configurationList) {
         List<String> metricConfigFiles = appConfig.getMetricConfigFiles();
         if (metricConfigFiles != null && !metricConfigFiles.isEmpty()) {
             log.warn("Loading files via metricConfigFiles setting is deprecated.  Please "
@@ -244,8 +243,8 @@ static void loadMetricConfigFiles(
                 log.info("Reading metric config file " + yamlPath);
                 try {
                     yamlInputStream = new FileInputStream(yamlPath);
-                    ArrayList<Map<String, Object>> confs =
-                            (ArrayList<Map<String, Object>>)
+                    List<Map<String, Object>> confs =
+                            (List<Map<String, Object>>)
                                     YAML.get().load(yamlInputStream);
                     for (Map<String, Object> conf : confs) {
                         configurationList.add(new Configuration(conf));
@@ -269,7 +268,7 @@ static void loadMetricConfigFiles(
 
     @VisibleForTesting
     static void loadMetricConfigResources(
-            AppConfig config, LinkedList<Configuration> configurationList) {
+            AppConfig config, List<Configuration> configurationList) {
         List<String> resourceConfigList = config.getMetricConfigResources();
         if (resourceConfigList != null) {
             ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
@@ -280,10 +279,10 @@ static void loadMetricConfigResources(
                     log.warn("Cannot find metric config resource" + resourceName);
                 } else {
                     try {
-                        Map<String, ArrayList<Map<String, Object>>> topYaml =
-                                (Map<String, ArrayList<Map<String, Object>>>)
+                        Map<String, List<Map<String, Object>>> topYaml =
+                                (Map<String, List<Map<String, Object>>>)
                                         YAML.get().load(inputStream);
-                        ArrayList<Map<String, Object>> jmxConf =
+                        List<Map<String, Object>> jmxConf =
                                 topYaml.get("jmx_metrics");
                         if (jmxConf != null) {
                             for (Map<String, Object> conf : jmxConf) {
@@ -395,7 +394,7 @@ public String toString() {
     }
 
     /** Returns a map of metrics collected. */
-    public LinkedList<HashMap<String, Object>> getMetrics() throws IOException {
+    public List<HashMap<String, Object>> getMetrics() throws IOException {
 
         // We can force to refresh the bean list every x seconds in case of ephemeral beans
         // To enable this, a "refresh_beans" parameter must be specified in the yaml/json config
@@ -407,7 +406,7 @@ public LinkedList<HashMap<String, Object>> getMetrics() throws IOException {
             this.getMatchingAttributes();
         }
 
-        LinkedList<HashMap<String, Object>> metrics = new LinkedList<HashMap<String, Object>>();
+        List<HashMap<String, Object>> metrics = new ArrayList<HashMap<String, Object>>();
         Iterator<JmxAttribute> it = matchingAttributes.iterator();
 
         // increment the lastCollectionTime
@@ -416,7 +415,7 @@ public LinkedList<HashMap<String, Object>> getMetrics() throws IOException {
         while (it.hasNext()) {
             JmxAttribute jmxAttr = it.next();
             try {
-                LinkedList<HashMap<String, Object>> jmxAttrMetrics = jmxAttr.getMetrics();
+                List<HashMap<String, Object>> jmxAttrMetrics = jmxAttr.getMetrics();
                 for (HashMap<String, Object> m : jmxAttrMetrics) {
                     m.put("check_name", this.checkName);
                     metrics.add(m);
@@ -614,7 +613,7 @@ private void getMatchingAttributes() throws IOException {
     }
 
     /** Returns a list of strings listing the bean scopes. */
-    public LinkedList<String> getBeansScopes() {
+    public List<String> getBeansScopes() {
         if (this.beanScopes == null) {
             this.beanScopes = Configuration.getGreatestCommonScopes(configurationList);
         }
@@ -628,13 +627,13 @@ public LinkedList<String> getBeansScopes() {
     private void refreshBeansList() throws IOException {
         this.beans = new HashSet<ObjectName>();
         String action = appConfig.getAction();
-        Boolean limitQueryScopes =
+        boolean limitQueryScopes =
                 !action.equals(AppConfig.ACTION_LIST_EVERYTHING)
                         && !action.equals(AppConfig.ACTION_LIST_NOT_MATCHING);
 
         if (limitQueryScopes) {
             try {
-                LinkedList<String> beanScopes = getBeansScopes();
+                List<String> beanScopes = getBeansScopes();
                 for (String scope : beanScopes) {
                     ObjectName name = new ObjectName(scope);
                     this.beans.addAll(connection.queryNames(name));
diff --git a/src/main/java/org/datadog/jmxfetch/JmxAttribute.java b/src/main/java/org/datadog/jmxfetch/JmxAttribute.java
index 86f62f30a..04e267585 100644
--- a/src/main/java/org/datadog/jmxfetch/JmxAttribute.java
+++ b/src/main/java/org/datadog/jmxfetch/JmxAttribute.java
@@ -8,7 +8,6 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -55,7 +54,7 @@ public abstract class JmxAttribute {
             new HashMap<String, Map<Object, Object>>();
     protected String[] tags;
     private Configuration matchingConf;
-    private LinkedList<String> defaultTagsList;
+    private List<String> defaultTagsList;
     private Boolean cassandraAliasing;
 
     JmxAttribute(
@@ -85,7 +84,7 @@ public abstract class JmxAttribute {
         this.domain = domain;
 
         HashMap<String, String> beanParametersHash = getBeanParametersHash(beanParameters);
-        LinkedList<String> beanParametersList =
+        List<String> beanParametersList =
                 getBeanParametersList(instanceName, beanParametersHash, instanceTags);
 
         this.beanParameters = beanParametersHash;
@@ -116,7 +115,7 @@ private void addAdditionalTags() {
         if (include != null) {
             for (Map.Entry<String, String> tag : include.getAdditionalTags().entrySet()) {
                 String alias = this.replaceByAlias(tag.getValue());
-                if ((alias.trim().length() > 0) && alias != null) {
+                if (alias != null && alias.trim().length() > 0) {
                     this.defaultTagsList.add(tag.getKey() + ":" + alias);
                 } else {
                     log.warn("Unable to apply tag " + tag.getKey() + " - with unknown alias");
@@ -141,11 +140,11 @@ public static HashMap<String, String> getBeanParametersHash(String beanParameter
         return beanParamsMap;
     }
 
-    private LinkedList<String> getBeanParametersList(
+    private List<String> getBeanParametersList(
             String instanceName,
             Map<String, String> beanParameters,
             Map<String, String> instanceTags) {
-        LinkedList<String> beanTags = new LinkedList<String>();
+        List<String> beanTags = new ArrayList<String>();
         beanTags.add("instance:" + instanceName);
         beanTags.add("jmx_domain:" + domain);
 
@@ -174,8 +173,8 @@ private LinkedList<String> getBeanParametersList(
      * Sanitize MBean parameter names and values, i.e. - Rename parameter names conflicting with
      * existing tags - Remove illegal characters
      */
-    private static LinkedList<String> sanitizeParameters(LinkedList<String> beanParametersList) {
-        LinkedList<String> defaultTagsList = new LinkedList<String>();
+    private static List<String> sanitizeParameters(List<String> beanParametersList) {
+        List<String> defaultTagsList = new ArrayList<String>(beanParametersList.size());
         for (String rawBeanParameter : beanParametersList) {
             // Remove `|` characters
             String beanParameter = rawBeanParameter.replace("|", "");
@@ -199,7 +198,7 @@ protected Boolean renameCassandraMetrics() {
     }
 
     private static Collection<String> getCassandraBeanTags(Map<String, String> beanParameters) {
-        Collection<String> tags = new LinkedList<String>();
+        Collection<String> tags = new ArrayList<String>();
         for (Map.Entry<String, String> param : beanParameters.entrySet()) {
             if (param.getKey().equals("name")) {
                 // This is already in the alias
@@ -233,7 +232,7 @@ public String toString() {
                 + attribute.getType();
     }
 
-    public abstract LinkedList<HashMap<String, Object>> getMetrics()
+    public abstract List<HashMap<String, Object>> getMetrics()
             throws AttributeNotFoundException, InstanceNotFoundException, MBeanException,
                     ReflectionException, IOException;
 
@@ -325,7 +324,7 @@ Object convertMetricValue(Object metricValue, String field) {
     }
 
     private boolean matchBeanRegex(Filter filter, boolean matchIfNoRegex) {
-        ArrayList<Pattern> beanRegexes = filter.getBeanRegexes();
+        List<Pattern> beanRegexes = filter.getBeanRegexes();
         if (beanRegexes.isEmpty()) {
             return matchIfNoRegex;
         }
@@ -355,7 +354,7 @@ private boolean matchBeanName(Configuration configuration) {
                 continue;
             }
 
-            ArrayList<String> beanValues = include.getParameterValues(beanAttr);
+            List<String> beanValues = include.getParameterValues(beanAttr);
 
             if (beanParameters.get(beanAttr) == null
                     || !(beanValues.contains(beanParameters.get(beanAttr)))) {
@@ -367,7 +366,7 @@ private boolean matchBeanName(Configuration configuration) {
 
     private boolean excludeMatchBeanName(Configuration conf) {
         Filter exclude = conf.getExclude();
-        ArrayList<String> beanNames = exclude.getBeanNames();
+        List<String> beanNames = exclude.getBeanNames();
 
         if (beanNames.contains(beanStringName)) {
             return true;
@@ -382,7 +381,7 @@ private boolean excludeMatchBeanName(Configuration conf) {
                 continue;
             }
 
-            ArrayList<String> beanValues = exclude.getParameterValues(beanAttr);
+            List<String> beanValues = exclude.getParameterValues(beanAttr);
             for (String beanVal : beanValues) {
                 if (beanParameters.get(beanAttr).equals(beanVal)) {
                     return true;
@@ -576,12 +575,12 @@ protected String[] getTags() {
         if (include != null) {
             Object includeAttribute = include.getAttribute();
             if (includeAttribute instanceof Map<?, ?>) {
-                Map<String, ArrayList<String>> attributeParams =
-                        ((Map<String, Map<String, ArrayList<String>>>)
+                Map<String, List<String>> attributeParams =
+                        ((Map<String, Map<String, List<String>>>)
                                         includeAttribute)
                                 .get(attributeName);
                 if (attributeParams != null) {
-                    ArrayList<String> yamlTags = attributeParams.get("tags");
+                    List<String> yamlTags = attributeParams.get("tags");
                     if (yamlTags != null) {
                         defaultTagsList.addAll(yamlTags);
                     }
diff --git a/src/main/java/org/datadog/jmxfetch/JmxComplexAttribute.java b/src/main/java/org/datadog/jmxfetch/JmxComplexAttribute.java
index a0d0fce89..a01ea6940 100644
--- a/src/main/java/org/datadog/jmxfetch/JmxComplexAttribute.java
+++ b/src/main/java/org/datadog/jmxfetch/JmxComplexAttribute.java
@@ -4,7 +4,7 @@
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import javax.management.AttributeNotFoundException;
 import javax.management.InstanceNotFoundException;
@@ -55,11 +55,12 @@ private void populateSubAttributeList(Object attributeValue) {
     }
 
     @Override
-    public LinkedList<HashMap<String, Object>> getMetrics()
+    public List<HashMap<String, Object>> getMetrics()
             throws AttributeNotFoundException, InstanceNotFoundException, MBeanException,
                     ReflectionException, IOException {
 
-        LinkedList<HashMap<String, Object>> metrics = new LinkedList<HashMap<String, Object>>();
+        List<HashMap<String, Object>> metrics = new ArrayList<HashMap<String, Object>>(
+                subAttributeList.entrySet().size());
 
         for (Map.Entry<String, HashMap<String, Object>> pair : subAttributeList.entrySet()) {
             String subAttribute = pair.getKey();
@@ -146,8 +147,8 @@ private boolean matchSubAttribute(
                 && ((Map<String, Object>) (params.getAttribute()))
                         .containsKey(subAttributeName)) {
             return true;
-        } else if ((params.getAttribute() instanceof ArrayList<?>
-                && ((ArrayList<String>) (params.getAttribute())).contains(subAttributeName))) {
+        } else if ((params.getAttribute() instanceof List<?>
+                && ((List<String>) (params.getAttribute())).contains(subAttributeName))) {
             return true;
         } else if (params.getAttribute() == null) {
             return matchOnEmpty;
diff --git a/src/main/java/org/datadog/jmxfetch/JmxSimpleAttribute.java b/src/main/java/org/datadog/jmxfetch/JmxSimpleAttribute.java
index e3f7cf983..a5ff3b50b 100644
--- a/src/main/java/org/datadog/jmxfetch/JmxSimpleAttribute.java
+++ b/src/main/java/org/datadog/jmxfetch/JmxSimpleAttribute.java
@@ -3,7 +3,7 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import javax.management.AttributeNotFoundException;
 import javax.management.InstanceNotFoundException;
@@ -36,7 +36,7 @@ public JmxSimpleAttribute(
     }
 
     @Override
-    public LinkedList<HashMap<String, Object>> getMetrics()
+    public List<HashMap<String, Object>> getMetrics()
             throws AttributeNotFoundException, InstanceNotFoundException, MBeanException,
                     ReflectionException, IOException {
         HashMap<String, Object> metric = new HashMap<String, Object>();
@@ -45,7 +45,7 @@ public LinkedList<HashMap<String, Object>> getMetrics()
         metric.put("value", castToDouble(getValue(), null));
         metric.put("tags", getTags());
         metric.put("metric_type", getMetricType());
-        LinkedList<HashMap<String, Object>> metrics = new LinkedList<HashMap<String, Object>>();
+        List<HashMap<String, Object>> metrics = new ArrayList<HashMap<String, Object>>(1);
         metrics.add(metric);
         return metrics;
     }
@@ -69,8 +69,8 @@ private boolean excludeMatchAttribute(Configuration configuration) {
                         .containsKey(getAttributeName())) {
             return true;
 
-        } else if ((exclude.getAttribute() instanceof ArrayList<?>
-                && ((ArrayList<String>) (exclude.getAttribute())).contains(getAttributeName()))) {
+        } else if ((exclude.getAttribute() instanceof List<?>
+                && ((List<String>) (exclude.getAttribute())).contains(getAttributeName()))) {
             return true;
         }
         return false;
@@ -86,8 +86,8 @@ private boolean matchAttribute(Configuration configuration) {
                         .containsKey(getAttributeName())) {
             return true;
 
-        } else if ((include.getAttribute() instanceof ArrayList<?>
-                && ((ArrayList<String>) (include.getAttribute())).contains(getAttributeName()))) {
+        } else if ((include.getAttribute() instanceof List<?>
+                && ((List<String>) (include.getAttribute())).contains(getAttributeName()))) {
             return true;
         }
 
diff --git a/src/main/java/org/datadog/jmxfetch/JmxTabularAttribute.java b/src/main/java/org/datadog/jmxfetch/JmxTabularAttribute.java
index 2e0a96b63..a8449adfe 100644
--- a/src/main/java/org/datadog/jmxfetch/JmxTabularAttribute.java
+++ b/src/main/java/org/datadog/jmxfetch/JmxTabularAttribute.java
@@ -10,7 +10,6 @@
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import javax.management.AttributeNotFoundException;
@@ -126,12 +125,11 @@ protected String[] getTags(String key, String subAttribute)
     }
 
     @Override
-    public LinkedList<HashMap<String, Object>> getMetrics()
+    public List<HashMap<String, Object>> getMetrics()
             throws AttributeNotFoundException, InstanceNotFoundException, MBeanException,
                     ReflectionException, IOException {
-        LinkedList<HashMap<String, Object>> metrics = new LinkedList<HashMap<String, Object>>();
-        HashMap<String, LinkedList<HashMap<String, Object>>> subMetrics =
-                new HashMap<String, LinkedList<HashMap<String, Object>>>();
+        HashMap<String, List<HashMap<String, Object>>> subMetrics =
+                new HashMap<String, List<HashMap<String, Object>>>();
 
         for (String dataKey : subAttributeList.keySet()) {
             HashMap<String, HashMap<String, Object>> subSub = subAttributeList.get(dataKey);
@@ -154,12 +152,14 @@ public LinkedList<HashMap<String, Object>> getMetrics()
 
                 String fullMetricKey = getAttributeName() + "." + metricKey;
                 if (!subMetrics.containsKey(fullMetricKey)) {
-                    subMetrics.put(fullMetricKey, new LinkedList<HashMap<String, Object>>());
+                    subMetrics.put(fullMetricKey, new ArrayList<HashMap<String, Object>>());
                 }
                 subMetrics.get(fullMetricKey).add(metric);
             }
         }
 
+        List<HashMap<String, Object>> metrics =
+                new ArrayList<HashMap<String, Object>>(subMetrics.keySet().size());
         for (String key : subMetrics.keySet()) {
             // only add explicitly included metrics
             if (getAttributesFor(key) != null) {
@@ -171,7 +171,7 @@ public LinkedList<HashMap<String, Object>> getMetrics()
     }
 
     private List<HashMap<String, Object>> sortAndFilter(
-            String metricKey, LinkedList<HashMap<String, Object>> metrics) {
+            String metricKey, List<HashMap<String, Object>> metrics) {
         Map<String, ?> attributes = getAttributesFor(metricKey);
         if (!attributes.containsKey("limit")) {
             return metrics;
@@ -287,8 +287,8 @@ private boolean matchSubAttribute(
                 && ((Map<String, Object>) (params.getAttribute()))
                         .containsKey(subAttributeName)) {
             return true;
-        } else if ((params.getAttribute() instanceof ArrayList<?>
-                && ((ArrayList<String>) (params.getAttribute())).contains(subAttributeName))) {
+        } else if ((params.getAttribute() instanceof List<?>
+                && ((List<String>) (params.getAttribute())).contains(subAttributeName))) {
             return true;
         } else if (params.getAttribute() == null) {
             return matchOnEmpty;
diff --git a/src/main/java/org/datadog/jmxfetch/MetricCollectionTask.java b/src/main/java/org/datadog/jmxfetch/MetricCollectionTask.java
index 12dd8b75d..6c6c7081d 100644
--- a/src/main/java/org/datadog/jmxfetch/MetricCollectionTask.java
+++ b/src/main/java/org/datadog/jmxfetch/MetricCollectionTask.java
@@ -2,25 +2,27 @@
 
 import lombok.extern.slf4j.Slf4j;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
-import java.util.LinkedList;
+import java.util.List;
 
 @Slf4j
-class MetricCollectionTask extends InstanceTask<LinkedList<HashMap<String, Object>>> {
+class MetricCollectionTask extends InstanceTask<List<HashMap<String, Object>>> {
     MetricCollectionTask(Instance instance) {
         super(instance);
         setWarning("Unable to collect metrics or refresh bean list.");
     }
 
     @Override
-    public LinkedList<HashMap<String, Object>> call() throws Exception {
+    public List<HashMap<String, Object>> call() throws Exception {
 
         if (!instance.timeToCollect()) {
             log.debug(
                     "it is not time to collect, skipping run for instance: " + instance.getName());
 
             // Maybe raise an exception here instead...
-            return new LinkedList<HashMap<String, Object>>();
+            return Collections.emptyList();
         }
 
         return instance.getMetrics();
diff --git a/src/main/java/org/datadog/jmxfetch/Status.java b/src/main/java/org/datadog/jmxfetch/Status.java
index 84e74495f..e85ba9dff 100644
--- a/src/main/java/org/datadog/jmxfetch/Status.java
+++ b/src/main/java/org/datadog/jmxfetch/Status.java
@@ -7,8 +7,9 @@
 import org.yaml.snakeyaml.Yaml;
 
 import java.io.File;
+import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.LinkedList;
+import java.util.List;
 
 @Slf4j
 public class Status {
@@ -81,15 +82,15 @@ private void addStats(
             String message,
             String status,
             String key) {
-        LinkedList<HashMap<String, Object>> checkStats;
+        List<HashMap<String, Object>> checkStats;
         HashMap<String, Object> initializedChecks;
         initializedChecks = (HashMap<String, Object>) this.instanceStats.get(key);
         if (initializedChecks == null) {
             initializedChecks = new HashMap<String, Object>();
         }
-        checkStats = (LinkedList<HashMap<String, Object>>) initializedChecks.get(checkName);
+        checkStats = (List<HashMap<String, Object>>) initializedChecks.get(checkName);
         if (checkStats == null) {
-            checkStats = new LinkedList<HashMap<String, Object>>();
+            checkStats = new ArrayList<HashMap<String, Object>>();
         }
         HashMap<String, Object> instStats = new HashMap<String, Object>();
         if (instance != null) {
diff --git a/src/main/java/org/datadog/jmxfetch/reporter/ConsoleReporter.java b/src/main/java/org/datadog/jmxfetch/reporter/ConsoleReporter.java
index 75bdd8b96..7e899bd57 100644
--- a/src/main/java/org/datadog/jmxfetch/reporter/ConsoleReporter.java
+++ b/src/main/java/org/datadog/jmxfetch/reporter/ConsoleReporter.java
@@ -7,15 +7,15 @@
 import org.datadog.jmxfetch.Instance;
 import org.datadog.jmxfetch.JmxAttribute;
 
+import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.LinkedList;
+import java.util.List;
 
 @Slf4j
 public class ConsoleReporter extends Reporter {
 
-    private LinkedList<HashMap<String, Object>> metrics = new LinkedList<HashMap<String, Object>>();
-    private LinkedList<HashMap<String, Object>> serviceChecks =
-            new LinkedList<HashMap<String, Object>>();
+    private List<HashMap<String, Object>> metrics = new ArrayList<HashMap<String, Object>>();
+    private List<HashMap<String, Object>> serviceChecks = new ArrayList<HashMap<String, Object>>();
 
     @Override
     protected void sendMetricPoint(
@@ -33,9 +33,9 @@ protected void sendMetricPoint(
     }
 
     /** Returns list of metrics to report and clears stored metric map. */
-    public LinkedList<HashMap<String, Object>> getMetrics() {
-        LinkedList<HashMap<String, Object>> returnedMetrics =
-                new LinkedList<HashMap<String, Object>>();
+    public List<HashMap<String, Object>> getMetrics() {
+        List<HashMap<String, Object>> returnedMetrics =
+                new ArrayList<HashMap<String, Object>>(metrics.size());
         for (HashMap<String, Object> map : metrics) {
             returnedMetrics.add(new HashMap<String, Object>(map));
         }
@@ -61,9 +61,9 @@ public void doSendServiceCheck(String checkName, String status, String message,
     }
 
     /** Returns list of service checks to report and clears stored service check map.. */
-    public LinkedList<HashMap<String, Object>> getServiceChecks() {
-        LinkedList<HashMap<String, Object>> returnedServiceChecks =
-                new LinkedList<HashMap<String, Object>>();
+    public List<HashMap<String, Object>> getServiceChecks() {
+        List<HashMap<String, Object>> returnedServiceChecks =
+                new ArrayList<HashMap<String, Object>>(serviceChecks.size());
         for (HashMap<String, Object> map : serviceChecks) {
             returnedServiceChecks.add(new HashMap<String, Object>(map));
         }
diff --git a/src/main/java/org/datadog/jmxfetch/reporter/JsonReporter.java b/src/main/java/org/datadog/jmxfetch/reporter/JsonReporter.java
index bfe82b5cf..1bc429523 100644
--- a/src/main/java/org/datadog/jmxfetch/reporter/JsonReporter.java
+++ b/src/main/java/org/datadog/jmxfetch/reporter/JsonReporter.java
@@ -10,21 +10,21 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
 
 @Slf4j
 public class JsonReporter extends Reporter {
 
-    private LinkedList<HashMap<String, Object>> metrics = new LinkedList<HashMap<String, Object>>();
+    private List<HashMap<String, Object>> metrics = new ArrayList<HashMap<String, Object>>();
 
     protected void sendMetricPoint(
             String metricType, String metricName, double value, String[] tags) {
         long currentTime = System.currentTimeMillis() / 1000L;
-        List<Object> point = new ArrayList<Object>();
+        List<Object> point = new ArrayList<Object>(2);
         point.add(currentTime);
         point.add(value);
-        List<Object> points = new ArrayList<Object>();
+        List<Object> points = new ArrayList<Object>(1);
         points.add(point);
         HashMap<String, Object> metric = new HashMap<String, Object>();
         metric.put("host", "default");
@@ -43,7 +43,7 @@ public void doSendServiceCheck(String checkName, String status, String message,
         aggregator.put("metrics", metrics);
         HashMap<String, Object> serie = new HashMap<String, Object>();
         serie.put("aggregator", aggregator);
-        List<Object> series = new ArrayList<Object>();
+        List<Map<String, Object>> series = new ArrayList<Map<String, Object>>(1);
         series.add(serie);
 
         System.out.println("=== JSON ===");
diff --git a/src/main/java/org/datadog/jmxfetch/reporter/Reporter.java b/src/main/java/org/datadog/jmxfetch/reporter/Reporter.java
index e97bbf087..d1101b0eb 100644
--- a/src/main/java/org/datadog/jmxfetch/reporter/Reporter.java
+++ b/src/main/java/org/datadog/jmxfetch/reporter/Reporter.java
@@ -9,7 +9,7 @@
 
 import java.util.Arrays;
 import java.util.HashMap;
-import java.util.LinkedList;
+import java.util.List;
 
 @Slf4j
 public abstract class Reporter {
@@ -47,7 +47,7 @@ public void clearCountersAggregator(String instanceName) {
 
     /** Submits the metrics in the implementing reporter. */
     public void sendMetrics(
-            LinkedList<HashMap<String, Object>> metrics,
+            List<HashMap<String, Object>> metrics,
             String instanceName,
             boolean canonicalRate) {
         HashMap<String, HashMap<String, Object>> instanceRatesAggregator;
diff --git a/src/test/java/org/datadog/jmxfetch/TestApp.java b/src/test/java/org/datadog/jmxfetch/TestApp.java
index 44c7449fb..f2f094587 100644
--- a/src/test/java/org/datadog/jmxfetch/TestApp.java
+++ b/src/test/java/org/datadog/jmxfetch/TestApp.java
@@ -10,7 +10,6 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.LinkedList;
 import java.util.List;
 import org.junit.Test;
 
@@ -54,7 +53,7 @@ public void testBeanTags() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // 14 = 13 metrics from java.lang + 1 metric explicitly defined in the yaml config file
         assertEquals(14, metrics.size());
@@ -80,7 +79,7 @@ public void testRegexpAliasing() throws Exception {
 
         // Collect metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // Assertions
 
@@ -113,7 +112,7 @@ public void testNoAliasOnDetailedAttribute() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // Assertions
 
@@ -147,7 +146,7 @@ public void testCassandraBean() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // 14 = 2*13 metrics from java.lang + 2*1 metric explicitly defined in the yaml config file
         assertEquals(28, metrics.size());
@@ -186,7 +185,7 @@ public void testCassandraDeprecatedBean() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // 14 = 13 metrics from java.lang + 1 metric explicitly defined in the yaml config file
         assertEquals(14, metrics.size());
@@ -210,7 +209,7 @@ public void testDomainInclude() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // First filter 29 = 13 metrics from java.lang + 16 metrics implicitly defined
         assertEquals(29, metrics.size());
@@ -228,7 +227,7 @@ public void testDomainExclude() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // First filter 14 = 13 metrics from java.lang + 2 metrics explicitly define- 1 implicitly
         // defined in the exclude section
@@ -248,7 +247,7 @@ public void testDomainRegex() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // First filter 15 = 13 metrics from java.lang + 3 metrics explicitly defined - 1 implicitly
         // defined in exclude section
@@ -265,7 +264,7 @@ public void testParameterMatch() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // 13 default metrics from java.lang
         assertEquals(13, metrics.size());
@@ -281,7 +280,7 @@ public void testListParamsInclude() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // First filter 14 = 13 metrics from java.lang + 1 metrics explicitly defined
         assertEquals(14, metrics.size());
@@ -297,7 +296,7 @@ public void testListParamsExclude() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // First filter 13 = 13 metrics from java.lang + 2 metrics explicitly defined - 2 explicitly
         // defined
@@ -314,7 +313,7 @@ public void testListBeansInclude() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // First filter 14 = 13 metrics from java.lang + 1 metrics explicitly defined
         assertEquals(14, metrics.size());
@@ -333,7 +332,7 @@ public void testListBeansRegexInclude() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // First filter 15 = 13 metrics from java.lang + 2 metrics explicitly defined
         assertEquals(15, metrics.size());
@@ -352,7 +351,7 @@ public void testListBeansRegexExclude() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // First filter 14 = 13 metrics from java.lang + 1 metrics explicitly defined
         assertEquals(14, metrics.size());
@@ -371,7 +370,7 @@ public void testListBeansExclude() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // First filter 14 = 13 metrics from java.lang + 1 metrics explicitly defined
         assertEquals(14, metrics.size());
@@ -402,7 +401,7 @@ public void testMetricTypes() throws Exception {
         initApplication("jmx_histogram.yaml");
 
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // We test for the presence and the value of the metrics we want to collect
         List<String> commonTags =
@@ -436,7 +435,7 @@ public void testExcludeTags() throws Exception {
         // We do a first collection
         initApplication("jmx_exclude_tags.yml");
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // We test for the presence and the value of the metrics we want to collect.
         // Tags "type", "newTag" and "env" should be excluded
@@ -460,7 +459,7 @@ public void testAdditionalTags() throws Exception {
         // We do a first collection
         initApplication("jmx_additional_tags.yml");
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // We test for the presence and the value of the metrics we want to collect.
         // Tags "type", "newTag" and "env" should be excluded
@@ -495,7 +494,7 @@ public void testApp() throws Exception {
         initApplication("jmx.yaml");
 
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // 29 = 13 metrics from java.lang + the 6 gauges we are explicitly collecting + 9 gauges
         // implicitly collected
@@ -609,7 +608,7 @@ public void testAppCanonicalRate() throws Exception {
         initApplication("jmx_canonical.yaml");
 
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // 28 = 13 metrics from java.lang + the 5 gauges we are explicitly collecting + 9 gauges
         // implicitly collected
@@ -769,7 +768,7 @@ public void testServiceDiscovery() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // 14 = 13 metrics from java.lang + 1 metric explicitly defined in the yaml config file
         assertEquals(63, metrics.size());
@@ -836,8 +835,8 @@ public void testServiceDiscoveryLong() throws Exception {
 
         // Collecting metrics
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
-        ArrayList<Instance> instances = getInstances();
+        List<HashMap<String, Object>> metrics = getMetrics();
+        List<Instance> instances = getInstances();
 
         assertEquals(35, metrics.size());
 
@@ -857,7 +856,7 @@ public void testMetricError() throws Exception {
         initApplication("jmx_cast.yaml");
 
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // 13 metrics from java.lang + 2 defined - 1 error
         assertEquals(14, metrics.size());
diff --git a/src/test/java/org/datadog/jmxfetch/TestCommon.java b/src/test/java/org/datadog/jmxfetch/TestCommon.java
index e1d0fb84c..8f32d063e 100644
--- a/src/test/java/org/datadog/jmxfetch/TestCommon.java
+++ b/src/test/java/org/datadog/jmxfetch/TestCommon.java
@@ -14,7 +14,6 @@
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 import javax.management.InstanceAlreadyExistsException;
@@ -35,9 +34,9 @@ public class TestCommon {
     AppConfig appConfig = spy(AppConfig.builder().build());
     App app;
     MBeanServer mbs;
-    ArrayList<ObjectName> objectNames = new ArrayList<ObjectName>();
-    LinkedList<HashMap<String, Object>> metrics;
-    LinkedList<HashMap<String, Object>> serviceChecks;
+    List<ObjectName> objectNames = new ArrayList<ObjectName>();
+    List<HashMap<String, Object>> metrics;
+    List<HashMap<String, Object>> serviceChecks;
 
     /** Setup logger. */
     @BeforeClass
@@ -143,7 +142,7 @@ protected void run() {
     }
 
     /** Return configured instances */
-    protected ArrayList<Instance> getInstances() {
+    protected List<Instance> getInstances() {
         return app.getInstances();
     }
 
@@ -153,12 +152,12 @@ protected Reporter getReporter() {
     }
 
     /** Return the metrics collected by JMXFetch. */
-    protected LinkedList<HashMap<String, Object>> getMetrics() {
+    protected List<HashMap<String, Object>> getMetrics() {
         return metrics;
     }
 
     /** Return the service checks collected by JMXFetch. */
-    protected LinkedList<HashMap<String, Object>> getServiceChecks() {
+    protected List<HashMap<String, Object>> getServiceChecks() {
         return ((ConsoleReporter) appConfig.getReporter()).getServiceChecks();
     }
 
@@ -330,8 +329,7 @@ public void assertMetric(String name, List<String> tags, int countTags, String m
      */
     public void assertCoverage() {
         int totalMetrics = 0;
-        LinkedList<HashMap<String, Object>> untestedMetrics =
-                new LinkedList<HashMap<String, Object>>();
+        List<HashMap<String, Object>> untestedMetrics = new ArrayList<HashMap<String, Object>>();
 
         for (HashMap<String, Object> m : metrics) {
             String mName = (String) (m.get("name"));
@@ -361,7 +359,7 @@ public void assertCoverage() {
      * @return String report
      */
     private static String generateReport(
-            LinkedList<HashMap<String, Object>> untestedMetrics, int totalMetricsCount) {
+            List<HashMap<String, Object>> untestedMetrics, int totalMetricsCount) {
         StringBuilder sb = new StringBuilder();
 
         // Compute indicators
diff --git a/src/test/java/org/datadog/jmxfetch/TestConfiguration.java b/src/test/java/org/datadog/jmxfetch/TestConfiguration.java
index d293a4d66..bb4d360b1 100644
--- a/src/test/java/org/datadog/jmxfetch/TestConfiguration.java
+++ b/src/test/java/org/datadog/jmxfetch/TestConfiguration.java
@@ -11,14 +11,14 @@
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
 public class TestConfiguration {
-    static LinkedList<Configuration> configurations = new LinkedList<Configuration>();
+    static List<Configuration> configurations = new ArrayList<Configuration>();
     static JsonParser adConfigs;
 
     /**
@@ -33,13 +33,13 @@ public static void init() throws FileNotFoundException, IOException {
         String yamlPath = f.getAbsolutePath();
         FileInputStream yamlInputStream = new FileInputStream(yamlPath);
         YamlParser fileConfig = new YamlParser(yamlInputStream);
-        ArrayList<Map<String, Object>> configInstances =
-                ((ArrayList<Map<String, Object>>) fileConfig.getYamlInstances());
+        List<Map<String, Object>> configInstances =
+                ((List<Map<String, Object>>) fileConfig.getYamlInstances());
 
         for (Map<String, Object> config : configInstances) {
             Object yamlConf = config.get("conf");
             for (Map<String, Object> conf :
-                    (ArrayList<Map<String, Object>>) (yamlConf)) {
+                    (List<Map<String, Object>>) (yamlConf)) {
                 configurations.add(new Configuration(conf));
             }
         }
@@ -69,12 +69,12 @@ public void testAutoDiscoveryConfigs()
         assertEquals(configurations.size(), 4);
         int nconfigs = 0;
         for (String check : configs.keySet()) {
-            ArrayList<Map<String, Object>> configInstances =
-                    ((ArrayList<Map<String, Object>>) adConfigs.getJsonInstances(check));
+            List<Map<String, Object>> configInstances =
+                    ((List<Map<String, Object>>) adConfigs.getJsonInstances(check));
             for (Map<String, Object> config : configInstances) {
                 Object jsonConf = config.get("conf");
                 for (Map<String, Object> conf :
-                        (ArrayList<Map<String, Object>>) (jsonConf)) {
+                        (List<Map<String, Object>>) (jsonConf)) {
                     configurations.add(new Configuration(conf));
                     nconfigs++;
                 }
@@ -100,12 +100,12 @@ public void testFiltersByDomain()
         // Private method reflection
         Method getIncludeFiltersByDomain =
                 Configuration.class.getDeclaredMethod(
-                        "getIncludeFiltersByDomain", LinkedList.class);
+                        "getIncludeFiltersByDomain", List.class);
         getIncludeFiltersByDomain.setAccessible(true);
 
         // Assert
-        HashMap<String, LinkedList<Filter>> filtersByDomain =
-                (HashMap<String, LinkedList<Filter>>)
+        HashMap<String, List<Filter>> filtersByDomain =
+                (HashMap<String, List<Filter>>)
                         getIncludeFiltersByDomain.invoke(null, configurations);
 
         // Only contains 'org.datadog.jmxfetch.test' domain
@@ -133,7 +133,7 @@ public void testCommonBeanKeys()
         // Private method reflection
         Method getIncludeFiltersByDomain =
                 Configuration.class.getDeclaredMethod(
-                        "getIncludeFiltersByDomain", LinkedList.class);
+                        "getIncludeFiltersByDomain", List.class);
         getIncludeFiltersByDomain.setAccessible(true);
 
         Method getCommonBeanKeysByDomain =
@@ -141,8 +141,8 @@ public void testCommonBeanKeys()
         getCommonBeanKeysByDomain.setAccessible(true);
 
         // Assert
-        HashMap<String, LinkedList<Filter>> filtersByDomain =
-                (HashMap<String, LinkedList<Filter>>)
+        HashMap<String, List<Filter>> filtersByDomain =
+                (HashMap<String, List<Filter>>)
                         getIncludeFiltersByDomain.invoke(null, configurations);
         HashMap<String, Set<String>> parametersIntersectionByDomain =
                 (HashMap<String, Set<String>>)
@@ -177,7 +177,7 @@ public void testCommonScope()
         // Private method reflection
         Method getIncludeFiltersByDomain =
                 Configuration.class.getDeclaredMethod(
-                        "getIncludeFiltersByDomain", LinkedList.class);
+                        "getIncludeFiltersByDomain", List.class);
         getIncludeFiltersByDomain.setAccessible(true);
 
         Method getCommonBeanKeysByDomain =
@@ -190,8 +190,8 @@ public void testCommonScope()
         getCommonScopeByDomain.setAccessible(true);
 
         // Assert
-        Map<String, LinkedList<Filter>> filtersByDomain =
-                (Map<String, LinkedList<Filter>>)
+        Map<String, List<Filter>> filtersByDomain =
+                (Map<String, List<Filter>>)
                         getIncludeFiltersByDomain.invoke(null, configurations);
         Map<String, Set<String>> parametersIntersectionByDomain =
                 (Map<String, Set<String>>)
diff --git a/src/test/java/org/datadog/jmxfetch/TestInstance.java b/src/test/java/org/datadog/jmxfetch/TestInstance.java
index 22f36f0d1..b2535bf73 100644
--- a/src/test/java/org/datadog/jmxfetch/TestInstance.java
+++ b/src/test/java/org/datadog/jmxfetch/TestInstance.java
@@ -9,9 +9,9 @@
 
 import com.google.common.collect.Lists;
 import java.net.URL;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
-import java.util.LinkedList;
 import java.util.List;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.LogManager;
@@ -26,7 +26,7 @@ public void testMinCollectionInterval() throws Exception {
         initApplication("jmx_min_collection_period.yml");
 
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
         assertEquals(15, metrics.size());
 
         run();
@@ -62,14 +62,14 @@ public void testEmptyDefaultHostname() throws Exception {
         initApplication("jmx_empty_default_hostname.yaml");
         run();
 
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
         assertEquals(28, metrics.size());
         for (HashMap<String, Object> metric : metrics) {
             String[] tags = (String[]) metric.get("tags");
             this.assertHostnameTags(Arrays.asList(tags));
         }
 
-        LinkedList<HashMap<String, Object>> serviceChecks = getServiceChecks();
+        List<HashMap<String, Object>> serviceChecks = getServiceChecks();
         assertEquals(2, serviceChecks.size());
         for (HashMap<String, Object> sc : serviceChecks) {
             String[] tags = (String[]) sc.get("tags");
@@ -82,7 +82,7 @@ public void testLoadMetricConfigFiles() throws Exception {
         URL defaultConfig = Instance.class.getResource("default-jmx-metrics.yaml");
         AppConfig config = mock(AppConfig.class);
         when(config.getMetricConfigFiles()).thenReturn(Lists.newArrayList(defaultConfig.getPath()));
-        LinkedList<Configuration> configurationList = new LinkedList<Configuration>();
+        List<Configuration> configurationList = new ArrayList<Configuration>();
         Instance.loadMetricConfigFiles(config, configurationList);
 
         assertEquals(2, configurationList.size());
@@ -94,7 +94,7 @@ public void testLoadMetricConfigResources() throws Exception {
         String configResource = defaultConfig.getPath().split("test-classes/")[1];
         AppConfig config = mock(AppConfig.class);
         when(config.getMetricConfigResources()).thenReturn(Lists.newArrayList(configResource));
-        LinkedList<Configuration> configurationList = new LinkedList<Configuration>();
+        List<Configuration> configurationList = new ArrayList<Configuration>();
         Instance.loadMetricConfigResources(config, configurationList);
 
         assertEquals(2, configurationList.size());
diff --git a/src/test/java/org/datadog/jmxfetch/TestServiceChecks.java b/src/test/java/org/datadog/jmxfetch/TestServiceChecks.java
index b33f8e375..46dce6e93 100644
--- a/src/test/java/org/datadog/jmxfetch/TestServiceChecks.java
+++ b/src/test/java/org/datadog/jmxfetch/TestServiceChecks.java
@@ -8,7 +8,8 @@
 
 import java.util.Arrays;
 import java.util.HashMap;
-import java.util.LinkedList;
+import java.util.List;
+
 import org.datadog.jmxfetch.reporter.Reporter;
 import org.junit.Test;
 
@@ -24,13 +25,13 @@ public void testServiceCheckOK() throws Exception {
         initApplication("jmx.yaml");
 
         run();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> metrics = getMetrics();
 
         // Test that an OK service check status is sent
-        LinkedList<HashMap<String, Object>> serviceChecks = getServiceChecks();
+        List<HashMap<String, Object>> serviceChecks = getServiceChecks();
 
         assertEquals(1, serviceChecks.size());
-        HashMap<String, Object> sc = serviceChecks.getFirst();
+        HashMap<String, Object> sc = serviceChecks.get(0);
         assertNotNull(sc.get("name"));
         assertNotNull(sc.get("status"));
         assertNull(sc.get("message"));
@@ -64,12 +65,12 @@ public void testServiceCheckWarning() throws Exception {
         run();
 
         // Test that an WARNING service check status is sent
-        LinkedList<HashMap<String, Object>> serviceChecks = getServiceChecks();
-        LinkedList<HashMap<String, Object>> metrics = getMetrics();
+        List<HashMap<String, Object>> serviceChecks = getServiceChecks();
+        List<HashMap<String, Object>> metrics = getMetrics();
         assertTrue(metrics.size() >= 350);
 
         assertEquals(1, serviceChecks.size());
-        HashMap<String, Object> sc = serviceChecks.getFirst();
+        HashMap<String, Object> sc = serviceChecks.get(0);
         assertNotNull(sc.get("name"));
         assertNotNull(sc.get("status"));
 
@@ -99,10 +100,10 @@ public void testServiceCheckCRITICAL() throws Exception {
         initApplication("non_running_process.yaml");
 
         // Test that a CRITICAL service check status is sent on initialization
-        LinkedList<HashMap<String, Object>> serviceChecks = getServiceChecks();
+        List<HashMap<String, Object>> serviceChecks = getServiceChecks();
         assertEquals(1, serviceChecks.size());
 
-        HashMap<String, Object> sc = serviceChecks.getFirst();
+        HashMap<String, Object> sc = serviceChecks.get(0);
         assertNotNull(sc.get("name"));
         assertNotNull(sc.get("status"));
         assertNotNull(sc.get("message"));
@@ -129,7 +130,7 @@ public void testServiceCheckCRITICAL() throws Exception {
         serviceChecks = getServiceChecks();
         assertEquals(1, serviceChecks.size());
 
-        sc = serviceChecks.getFirst();
+        sc = serviceChecks.get(0);
         assertNotNull(sc.get("name"));
         assertNotNull(sc.get("status"));
         assertNotNull(sc.get("message"));