Bug fix

README.md

@@ -27,19 +27,17 @@ Under tab "Available Plugins", select "SSHMon Samples Collector", then click "Ap
 
 ### Via Package from [JMeter-Plugins.org](https://jmeter-plugins.org/)
 
-Extract the [zip package](https://jmeter-plugins.org/files/packages/tilln-sshmon-1.0.zip) into JMeter's lib directory, then restart JMeter.
+Extract the [zip package](https://jmeter-plugins.org/files/packages/tilln-sshmon-1.1.zip) into JMeter's lib directory, then restart JMeter.
 
 ### Via Manual Download
 
-1. Copy the [jmeter-sshmon jar file](https://github.com/tilln/jmeter-sshmon/releases/download/1.0/jmeter-sshmon-1.0.jar) into JMeter's lib/ext directory.
+1. Copy the [jmeter-sshmon jar file](https://github.com/tilln/jmeter-sshmon/releases/download/1.1/jmeter-sshmon-1.1.jar) into JMeter's lib/ext directory.
 2. Copy the following dependencies into JMeter's lib directory:
-	* [kg.apc / jmeter-plugins-cmn-jmeter](https://search.maven.org/remotecontent?filepath=kg/apc/jmeter-plugins-cmn-jmeter/0.5/jmeter-plugins-cmn-jmeter-0.5.jar)
-    * [commons-io / commons-io](https://search.maven.org/remotecontent?filepath=commons-io/commons-io/2.5/commons-io-2.5.jar)
-    * [org.apache.commons / commons-pool](https://search.maven.org/remotecontent?filepath=org/apache/commons/commons-pool2/2.4.2/commons-pool2-2.4.2.jar)
+	* [kg.apc / jmeter-plugins-cmn-jmeter](https://search.maven.org/remotecontent?filepath=kg/apc/jmeter-plugins-cmn-jmeter/0.6/jmeter-plugins-cmn-jmeter-0.6.jar)
     * [com.jcraft.jsch / jsch](https://search.maven.org/remotecontent?filepath=com/jcraft/jsch/0.1.54/jsch-0.1.54.jar)
 3. Restart JMeter.
 
-**Important: Make sure to remove any older jar file version than `jmeter-plugins-cmn-jmeter-0.5.jar` from JMeter's lib directory!**
+**Important: Make sure to remove any older jar file version than `jmeter-plugins-cmn-jmeter-0.6.jar` from JMeter's lib directory!**
 
 Usage
 -----
@@ -100,13 +98,21 @@ For details refer to the [JMeter-Plugins wiki](https://jmeter-plugins.org/wiki/S
 ### JMeter Properties
 
 The following properties control the plugin behaviour:
-  * `jmeter.sshmon.knownHosts`: Filename of a known_hosts file containing public keys of trusted remote servers (in OpenSSH format). If not set, no validation will be performed.
-  * `jmeter.sshmon.interval`: Define the metrics collection interval in milliseconds (default=1 second).
-  * `jmeter.sshmon.forceOutputFile` - (true/false) makes sure JMeter writes metrics to CSV file in the current directory if no filename is specified (default=false).
+  * `jmeter.sshmon.knownHosts`: Filename of a known_hosts file containing public keys of trusted remote servers (in OpenSSH format).
+    If defined, connections to unknown hosts will be rejected (via `StrictHostKeyChecking=yes`).
+    If undefined, connections to unknown hosts will be established (via `StrictHostKeyChecking=no`).
+    Default: undefined.
+  * `jmeter.sshmon.interval`: Metrics collection interval in milliseconds.
+    This is inclusive of the execution time of the remote commands.
+    Default: 1 second.
+  * `jmeter.sshmon.forceOutputFile` (true/false): Makes sure JMeter writes metrics to CSV file in the current directory if no filename is specified.
+    Default: false.
 
 Limitations
 -----------
 
-* Samples are collected by a single thread, so if the command takes more than an insignificant amount of time to run, the frequency of sample collection will be limited.
-A separate monitor may be used in this case.
-* The help link on the plugin GUI currently points to an incorrect location. This is to be resolved with the next release of `jmeter-plugins-cmn-jmeter` (see [this PR](https://github.com/undera/jmeter-plugins/pull/162)).
+* Samples are collected by a single thread, so if a command takes more than an insignificant amount of time to run, the frequency of sample collection will be limited.
+Even more so if more than one command is sampled. In this case, use a separate monitor for each sample command.
+* When a JMeter test ends, this plugin will not interrupt the collector thread but let the current sample finish before stopping.
+This may take longer than the JMeter engine [waits](https://jmeter.apache.org/usermanual/get-started.html#shutdown) in headless (non-GUI) mode.
+In this case, increase the JMeter property `jmeter.exit.check.pause`.

pom.xml

@@ -4,12 +4,13 @@
     <groupId>co.nz.breakpoint.jmeter</groupId>
     <artifactId>jmeter-sshmon</artifactId>
     <packaging>jar</packaging>
-    <version>1.0</version>
+    <version>1.1</version>
     <name>jmeter-sshmon</name>
-    <url>http://maven.apache.org</url>
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
     </properties>
 
     <scm>
@@ -80,7 +81,6 @@
                                     <goal>start</goal>
                                 </goals>
                                 <configuration>
-                                    <skip>true</skip>
                                     <arguments>
                                         <argument>java</argument>
                                         <argument>-cp</argument>
@@ -130,7 +130,7 @@
         <dependency>
             <groupId>kg.apc</groupId>
             <artifactId>jmeter-plugins-cmn-jmeter</artifactId>
-            <version>0.5</version>
+            <version>0.6</version>
         </dependency>
         <dependency>
             <groupId>com.jcraft</groupId>
@@ -140,12 +140,8 @@
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-pool2</artifactId>
-            <version>2.4.2</version>
-        </dependency>
-        <dependency>
-            <groupId>commons-io</groupId>
-            <artifactId>commons-io</artifactId>
-            <version>2.5</version>
+            <version>2.6.0</version>
+            <scope>provided</scope>
         </dependency>
         <dependency>
             <groupId>kg.apc</groupId>

src/main/java/nz/co/breakpoint/jmeter/vizualizers/sshmon/JSchLogger.java

@@ -0,0 +1,34 @@
+package nz.co.breakpoint.jmeter.vizualizers.sshmon;
+
+import java.util.HashMap;
+import java.util.Map;
+import com.jcraft.jsch.Logger;
+import org.apache.jorphan.logging.LoggingManager;
+import org.apache.log.Priority;
+
+class JSchLogger implements Logger {
+
+    private static final org.apache.log.Logger log = LoggingManager.getLoggerForClass();
+
+    private static final Map<Integer, Priority> levels = new HashMap<Integer, Priority>();
+    static {
+        levels.put(Logger.DEBUG, Priority.DEBUG);
+        levels.put(Logger.INFO, Priority.INFO);
+        levels.put(Logger.WARN, Priority.WARN);
+        levels.put(Logger.ERROR, Priority.ERROR);
+        levels.put(Logger.FATAL, Priority.FATAL_ERROR);
+    }
+
+    @Override
+    public boolean isEnabled(int level) {
+        return log.isPriorityEnabled(levels.get(level));
+    }
+
+    @Override
+    public void log(int level, String message) {
+        Priority p = levels.get(level);
+        if (p != null) {
+            log.log(p, message);
+        }
+    }
+}

src/main/java/nz/co/breakpoint/jmeter/vizualizers/sshmon/SSHMonCollector.java

@@ -53,4 +53,10 @@ protected void initiateConnectors() {
             samplers.add(new SSHMonSampler(label, connectionDetails, command, isDelta));
         }
     }
+
+    @Override
+    public void testEnded(String host) {
+        super.testEnded(host);
+        SSHMonSampler.clearConnectionPool();
+    }
 }

src/main/java/nz/co/breakpoint/jmeter/vizualizers/sshmon/SSHMonSampler.java

@@ -1,11 +1,10 @@
 package nz.co.breakpoint.jmeter.vizualizers.sshmon;
 
-import java.io.InterruptedIOException;
+import java.io.ByteArrayOutputStream;
 
 import kg.apc.jmeter.vizualizers.MonitoringSampler;
 import kg.apc.jmeter.vizualizers.MonitoringSampleGenerator;
 
-import org.apache.commons.io.IOUtils;
 import org.apache.commons.pool2.KeyedObjectPool;
 import org.apache.commons.pool2.impl.GenericKeyedObjectPool;
 import org.apache.commons.pool2.impl.GenericKeyedObjectPoolConfig;
@@ -35,12 +34,23 @@ public class SSHMonSampler
      */
     private static KeyedObjectPool<ConnectionDetails, Session> pool;
     static {
-        GenericKeyedObjectPoolConfig config = new GenericKeyedObjectPoolConfig();
+        GenericKeyedObjectPoolConfig<Session> config = new GenericKeyedObjectPoolConfig<>();
         config.setMinIdlePerKey(1);
+        config.setTestOnBorrow(true);
         log.debug("Creating GenericKeyedObjectPool");
         pool = new GenericKeyedObjectPool<ConnectionDetails, Session>(new SSHSessionFactory(), config);
     }
 
+    public static void clearConnectionPool() {
+        log.debug("Clearing connection pool");
+        try {
+            pool.clear();
+        }
+        catch (Exception e) {
+            log.error("Failed to clear connection pool: ", e);
+        }
+    }
+
     public SSHMonSampler(String name, ConnectionDetails connectionDetails, String remoteCommand, boolean sampleDeltaValue) {
         this.metricName = name;
         this.connectionDetails = connectionDetails;
@@ -52,6 +62,7 @@ public SSHMonSampler(String name, ConnectionDetails connectionDetails, String re
     public void generateSamples(MonitoringSampleGenerator collector) {
         Session session = null;
         ChannelExec channel = null;
+        ByteArrayOutputStream result = new ByteArrayOutputStream();
 
         try {
             log.debug("Borrowing session for "+connectionDetails);
@@ -60,10 +71,14 @@ public void generateSamples(MonitoringSampleGenerator collector) {
             channel = (ChannelExec)session.openChannel("exec");
             channel.setCommand(remoteCommand);
             channel.setPty(true);
+            channel.setOutputStream(result);
             channel.connect();
-
-            final double val = Double.valueOf(IOUtils.toString(channel.getInputStream()).trim());
 
+            while (!channel.isClosed()) { // wait for command execution to finish
+                Thread.sleep(10);
+            }
+
+            final double val = Double.valueOf(result.toString());
             if (sampleDeltaValue) {
                 if (!Double.isNaN(oldValue)) {
                     collector.generateSample(val - oldValue, metricName);
@@ -73,31 +88,30 @@ public void generateSamples(MonitoringSampleGenerator collector) {
                 collector.generateSample(val, metricName);
             }
         }
-        catch (InterruptedIOException ex) { // stopping the test has caused a thread interrupt
-            log.info(ex.toString());
+        catch (JSchException ex) {
+            log.error("Channel failure for "+connectionDetails, ex);
         }
-        catch (Exception ex) { 
-            log.error(ex.toString());
+        catch (Exception ex) {
+            log.error("Sample failure for "+connectionDetails, ex);
         }
         finally {
-            if (channel != null && channel.isConnected()) {
+            if (channel != null) {
+                log.debug("Disconnecting channel for "+connectionDetails);
                 channel.disconnect();
             }
-            if (session != null) {
-                try {
-                    if (session.isConnected()) {
-                        log.debug("Returning session for "+connectionDetails);
-                        pool.returnObject(connectionDetails, session);
-                    }
-                    else {
-                        log.debug("Invalidating session for "+connectionDetails);
-                        pool.invalidateObject(connectionDetails, session);
-                    }
+            try {
+                if (session != null && session.isConnected()) {
+                    log.debug("Returning session for "+connectionDetails);
+                    pool.returnObject(connectionDetails, session);
                 }
-                catch (Exception ex) {
-                    log.warn(ex.getMessage());
+                else {
+                    log.debug("Invalidating session for "+connectionDetails);
+                    pool.invalidateObject(connectionDetails, session);
                 }
             }
+            catch (Exception ex) {
+                log.warn("Failure returning session ", ex);
+            }
         }
     }
 

src/main/java/nz/co/breakpoint/jmeter/vizualizers/sshmon/SSHSessionFactory.java

@@ -17,16 +17,21 @@ public class SSHSessionFactory extends BaseKeyedPooledObjectFactory<ConnectionDe
 
     private static final Logger log = LoggingManager.getLoggerForClass();
 
-    private final JSch jsch = new JSch();
-    private boolean hostKeyValidation = false;
+    private final JSch jsch;
 
     public SSHSessionFactory() {
+        JSch.setLogger(new JSchLogger());
+        jsch = new JSch();
+
+        // Change default from "ask" to avoid interactive confirmation:
+        JSch.setConfig("StrictHostKeyChecking", "no");
+
         String knownHosts = JMeterUtils.getProperty("jmeter.sshmon.knownHosts");
         if (knownHosts != null && !knownHosts.isEmpty()) {
             try {
                 log.debug("known hosts file set to "+knownHosts);
                 jsch.setKnownHosts(knownHosts);
-                hostKeyValidation = true;
+                JSch.setConfig("StrictHostKeyChecking", "yes");
             }
             catch (JSchException e) {
                 log.error("Failed to set known hosts ", e);
@@ -45,9 +50,7 @@ public Session create(ConnectionDetails connectionDetails) throws Exception {
             }
             session = jsch.getSession(connectionDetails.getUsername(), connectionDetails.getHost(), connectionDetails.getPort());
             session.setPassword(connectionDetails.getPassword());
-            if (!hostKeyValidation) {
-                session.setConfig("StrictHostKeyChecking", "no");
-            }
+            session.setServerAliveCountMax(Integer.MAX_VALUE); // change from default value 1 to prevent disconnects
             session.setDaemonThread(true);
             session.connect();
         } catch (Exception e) {
@@ -59,7 +62,7 @@ public Session create(ConnectionDetails connectionDetails) throws Exception {
 
     @Override
     public PooledObject<Session> wrap(Session session) {
-        return new DefaultPooledObject(session);
+        return new DefaultPooledObject<Session>(session);
     }
 
     @Override