Async consumers for multiprocessing (#2)

* Fix up warning about the unclosed app context.

* Slap together async-consumer stuff.

* Add separator for asyncConsumer parameter.

* Update example as suggested.

README.md

@@ -37,20 +37,25 @@ error.maxRedeliveries=4
 This defines how many times to retry a message before failing completely.
 
 There are also common ActiveMQ properties to setup the connection.
+
 ```
 # ActiveMQ options
 jms.brokerUrl=tcp://localhost:61616
 ```
+
 This defines the url to the ActiveMQ broker.
+
 ```
 jms.username=
 jms.password=
 ```
 This defines the login credentials (if required)
+
 ```
 jms.connections=10
 ```
 This defines the pool of connections to the ActiveMQ instance.
+
 ```
 jms.concurrent-consumers=1
 ```
@@ -66,19 +71,24 @@ It's properties are:
 # Fcrepo indexer options
 fcrepo.indexer.enabled=true
 ```
+
 This defines whether the Fedora indexer is enabled or not.
+
 ```
 fcrepo.indexer.node=queue:islandora-indexing-fcrepo-content
 fcrepo.indexer.delete=queue:islandora-indexing-fcrepo-delete
 fcrepo.indexer.media=queue:islandora-indexing-fcrepo-media
 fcrepo.indexer.external=queue:islandora-indexing-fcrepo-file-external
 ```
+
 These define the various queues to listen on for the indexing/deletion
 messages. The part after `queue:` should match your Islandora instance "Actions".
+
 ```
 fcrepo.indexer.milliner.baseUrl=http://localhost:8000/milliner
 ```
 This defines the location of your Milliner microservice.
+
 ```
 fcrepo.indexer.concurrent-consumers=1
 fcrepo.indexer.max-concurrent-consumers=1
@@ -87,6 +97,12 @@ These define the default number of concurrent consumers and maximum number of co
 consumers working off your ActiveMQ instance.
 A value of `-1` means no setting is applied.
 
+```
+fcrepo.indexer.async-consumer=true
+```
+
+This property allows the concurrent consumers to process concurrently; otherwise, the consumers will wait to the previous message has been processed before executing.
+
 ### islandora-indexing-triplestore
 
 This service indexes the Drupal node into the configured triplestore
@@ -97,25 +113,39 @@ It's properties are:
 # Triplestore indexer options
 triplestore.indexer.enabled=false
 ```
+
 This defines whether the Triplestore indexer is enabled or not.
+
 ```
 triplestore.index.stream=queue:islandora-indexing-triplestore-index
 triplestore.delete.stream=queue:islandora-indexing-triplestore-delete
 ```
+
 These define the various queues to listen on for the indexing/deletion
 messages. The part after `queue:` should match your Islandora instance "Actions".
+
 ```
 triplestore.baseUrl=http://localhost:8080/bigdata/namespace/kb/sparql
 ```
+
 This defines the location of your triplestore's SPARQL update endpoint.
+
 ```
 triplestore.indexer.concurrent-consumers=1
 triplestore.indexer.max-concurrent-consumers=1
 ```
+
 These define the default number of concurrent consumers and maximum number of concurrent
 consumers working off your ActiveMQ instance.
 A value of `-1` means no setting is applied.
 
+
+```
+triplestore.indexer.async-consumer=true
+```
+
+This property allows the concurrent consumers to process concurrently; otherwise, the consumers will wait to the previous message has been processed before executing.
+
 ### islandora-connector-derivative
 
 This service is used to configure an external microservice. This service will deploy multiple copies of its routes
@@ -127,25 +157,40 @@ a comma separated list. Each item in the list defines a new route and must also
 ```
 derivative.<item>.enabled=true
 ```
+
 This defines if the `item` service is enabled.
+
 ```
 derivative.<item>.in.stream=queue:islandora-item-connector.index
 ```
+
 This is the input queue for the derivative microservice.
 The part after `queue:` should match your Islandora instance "Actions".
+
 ```
 derivative.<item>.service.url=http://example.org/derivative/convert
 ```
+
 This is the microservice URL to process the request.
+
 ```
 derivative.<item>.concurrent-consumers=1
 derivative.<item>.max-concurrent-consumers=1
 ```
+
 These define the default number of concurrent consumers and maximum number of concurrent
 consumers working off your ActiveMQ instance.
 A value of `-1` means no setting is applied.
 
+
+```
+derivative.<item>.async-consumer=true
+```
+
+This property allows the concurrent consumers to process concurrently; otherwise, the consumers will wait to the previous message has been processed before executing.
+
 For example, with two services defined (houdini and crayfits) my configuration would have
+
 ```
 derivative.systems.installed=houdini,fits
 
@@ -154,23 +199,27 @@ derivative.houdini.in.stream=queue:islandora-connector-houdini
 derivative.houdini.service.url=http://127.0.0.1:8000/houdini/convert
 derivative.houdini.concurrent-consumers=1
 derivative.houdini.max-concurrent-consumers=4
+derivative.houdini.async-consumer=true
 
 derivative.fits.enabled=true
 derivative.fits.in.stream=queue:islandora-connector-fits
 derivative.fits.service.url=http://127.0.0.1:8000/crayfits
 derivative.fits.concurrent-consumers=2
 derivative.fits.max-concurrent-consumers=2
+derivative.fits.async-consumer=false
 ```
 
 ### Customizing HTTP client timeouts
 
 You can alter the HTTP client from the defaults for its request, connection and socket timeouts.
 To do this you want to enable the request configurer.
+
 ```shell
 request.configurer.enabled=true
 ```
 
 Then set the next 3 timeouts (measured in milliseconds) to the desired timeout.
+
 ```shell
 request.timeout=-1
 connection.timeout=-1
@@ -182,6 +231,7 @@ The default for all three is `-1` which indicates no timeout.
 ## Deploying/Running
 
 You can see the options by passing the `-h|--help` flag
+
 ```shell
 > java -jar  islandora-alpaca-app/build/libs/islandora-alpaca-app-2.0.0-all.jar -h
 Usage: alpaca [-hV] [-c=<configurationFilePath>]
@@ -192,6 +242,7 @@ Usage: alpaca [-hV] [-c=<configurationFilePath>]
 ```
 
 Using the `-V|--version` flag will just return the current version of the application.
+
 ```shell
 > java -jar  islandora-alpaca-app/build/libs/islandora-alpaca-app-2.0.0-all.jar -v
 2.0.0
@@ -212,6 +263,7 @@ Logging is done to the console, and defaults to the INFO level. To get more verb
 can use the Java property `islandora.alpaca.log`
 
 i.e.
+
 ```shell
 java -Dislandora.alpaca.log=DEBUG -jar islandora-alpaca-app-2.0.0-all.jar -c /opt/my.properties
 ```

example.properties

@@ -21,6 +21,7 @@ fcrepo.indexer.external=queue:islandora-indexing-fcrepo-file-external
 fcrepo.indexer.milliner.baseUrl=http://127.0.0.1:8000/milliner/
 fcrepo.indexer.concurrent-consumers=-1
 fcrepo.indexer.max-concurrent-consumers=-1
+fcrepo.indexer.async-consumer=false
 
 # Triplestore indexer options
 triplestore.indexer.enabled=true
@@ -29,6 +30,7 @@ triplestore.index.stream=queue:islandora-indexing-triplestore-index
 triplestore.delete.stream=queue:islandora-indexing-triplestore-delete
 triplestore.indexer.concurrent-consumers=-1
 triplestore.indexer.max-concurrent-consumers=-1
+triplestore.indexer.async-consumer=false
 
 # Derivative services
 derivative.systems.installed=fits,homarus,houdini,ocr
@@ -38,21 +40,25 @@ derivative.fits.in.stream=queue:islandora-connector-fits
 derivative.fits.service.url=http://localhost:8000/crayfits
 derivative.fits.concurrent-consumers=-1
 derivative.fits.max-concurrent-consumers=-1
+derivative.fits.async-consumer=false
 
 derivative.homarus.enabled=true
 derivative.homarus.in.stream=queue:islandora-connector-homarus
 derivative.homarus.service.url=http://127.0.0.1:8000/homarus/convert
 derivative.homarus.concurrent-consumers=-1
 derivative.homarus.max-concurrent-consumers=-1
+derivative.homarus.async-consumer=false
 
 derivative.houdini.enabled=true
 derivative.houdini.in.stream=queue:islandora-connector-houdini
 derivative.houdini.service.url=http://127.0.0.1:8000/houdini/convert
 derivative.houdini.concurrent-consumers=-1
 derivative.houdini.max-concurrent-consumers=-1
+derivative.houdini.async-consumer=false
 
 derivative.ocr.enabled=true
 derivative.ocr.in.stream=queue:islandora-connector-ocr
 derivative.ocr.service.url=http://localhost:8000/hypercube
 derivative.ocr.concurrent-consumers=-1
 derivative.ocr.max-concurrent-consumers=-1
+derivative.ocr.async-consumer=false

islandora-alpaca-app/src/main/java/ca/islandora/alpaca/driver/AlpacaDriver.java

@@ -54,17 +54,21 @@ public Integer call() throws Exception {
             System.setProperty(ALPACA_CONFIG_PROPERTY, configurationFilePath.toFile().getAbsolutePath());
         }
         final var appContext = new AnnotationConfigApplicationContext("ca.islandora.alpaca");
-        appContext.start();
-        LOGGER.info("Alpaca started.");
+        try {
+            appContext.start();
+            LOGGER.info("Alpaca started.");
 
-        while (appContext.isRunning()) {
-            try {
-                Thread.sleep(1000);
-            } catch (final InterruptedException e) {
-                throw new RuntimeException("This should never happen");
+            while (appContext.isRunning()) {
+                try {
+                    Thread.sleep(1000);
+                } catch (final InterruptedException e) {
+                    throw new RuntimeException("This should never happen");
+                }
             }
+            return 0;
+        } finally {
+            appContext.close();
         }
-        return 0;
     }
 
     /**

islandora-connector-derivative/src/main/java/ca/islandora/alpaca/connector/derivative/DerivativeOptions.java

@@ -50,6 +50,7 @@ public class DerivativeOptions extends PropertyConfig {
   private static final String DERIVATIVE_OUTPUT_PROPERTY = "service.url";
   private static final String DERIVATIVE_CONCURRENT_PROPERTY = "concurrent-consumers";
   private static final String DERIVATIVE_MAX_CONCURRENT_PROPERTY = "max-concurrent-consumers";
+  private static final String DERIVATIVE_ASYNC_CONSUMER = "async-consumer";
 
   @Autowired
   private Environment environment;
@@ -104,8 +105,11 @@ private void startDerivativeService(final String serviceName) throws Exception {
                 Integer.class, -1);
         final int maxConcurrentConsumers = environment.getProperty(maxConcurrentConsumerProperty(serviceName),
                 Integer.class, -1);
+        final boolean asyncConsumer = environment.getProperty(asyncConsumerProperty(serviceName),
+                Boolean.class, false);
         // Add concurrent/max-concurrent
-        final String finalInput = addJmsOptions(addBrokerName(input), concurrentConsumers, maxConcurrentConsumers);
+        final String finalInput = addJmsOptions(addBrokerName(input), concurrentConsumers, maxConcurrentConsumers,
+                asyncConsumer);
         // Add connectionClose and other http options.
         final String finalOutput = addHttpOptions(output);
         camelContext.addRoutes(new DerivativeConnector(serviceName, finalInput, finalOutput, this));
@@ -180,4 +184,13 @@ private String maxConcurrentConsumerProperty(final String systemName) {
     return DERIVATIVE_PREFIX + "." + systemName + "." + DERIVATIVE_MAX_CONCURRENT_PROPERTY;
   }
 
+  /**
+   * Return the expected async-consumer property.
+   * @param systemName the derivative system name
+   * @return the property
+   */
+  private String asyncConsumerProperty(final String systemName) {
+      return DERIVATIVE_PREFIX + "." + systemName + "." + DERIVATIVE_ASYNC_CONSUMER;
+  }
+
 }

islandora-indexing-fcrepo/src/main/java/ca/islandora/alpaca/indexing/fcrepo/FcrepoIndexerOptions.java

@@ -43,6 +43,7 @@ public class FcrepoIndexerOptions extends PropertyConfig {
   private static final String FCREPO_BASE_URI_HEADER_PROPERTY = "fcrepo.indexer.fedoraHeader";
   private static final String FCREPO_INDEXER_CONCURRENT = "fcrepo.indexer.concurrent-consumers";
   private static final String FCREPO_INDEXER_MAX_CONCURRENT = "fcrepo.indexer.max-concurrent-consumers";
+  private static final String FCREPO_INDEXER_ASYNC_CONSUMER = "fcrepo.indexer.async-consumer";
 
   @Value("${" + FCREPO_INDEXER_NODE_INDEX + ":}")
   private String fcrepoNodeIndex;
@@ -68,6 +69,9 @@ public class FcrepoIndexerOptions extends PropertyConfig {
   @Value("${" + FCREPO_INDEXER_MAX_CONCURRENT + ":-1}")
   private int fcrepoMaxConcurrentConsumers;
 
+  @Value("${" + FCREPO_INDEXER_ASYNC_CONSUMER + ":false}")
+  private boolean fcrepoAsyncConsumers;
+
   /**
    * Defines that Fedora indexer is only enabled if the appropriate property is set to "true".
    */
@@ -113,7 +117,7 @@ public String getExternalIndex() {
    *   The altered topic/queue string.
    */
   private String addConcurrent(final String queueString) {
-    return addJmsOptions(queueString, fcrepoConcurrentConsumers, fcrepoMaxConcurrentConsumers);
+    return addJmsOptions(queueString, fcrepoConcurrentConsumers, fcrepoMaxConcurrentConsumers, fcrepoAsyncConsumers);
   }
 
   /**

islandora-indexing-triplestore/src/main/java/ca/islandora/alpaca/indexing/triplestore/TriplestoreIndexerOptions.java

@@ -43,6 +43,7 @@ public class TriplestoreIndexerOptions extends PropertyConfig {
   private static final String TRIPLESTORE_DELETE_QUEUE = "triplestore.delete.stream";
   private static final String TRIPLESTORE_CONCURRENT = "triplestore.indexer.concurrent-consumers";
   private static final String TRIPLESTORE_MAX_CONCURRENT = "triplestore.indexer.max-concurrent-consumers";
+  private static final String TRIPLESTORE_ASYNC_CONSUMER = "triplestore.indexer.async-consumer";
 
   @Value("${" + TRIPLESTORE_INDEX_QUEUE + ":}")
   private String jmsIndexStream;
@@ -59,6 +60,9 @@ public class TriplestoreIndexerOptions extends PropertyConfig {
   @Value("${" + TRIPLESTORE_MAX_CONCURRENT + ":-1}")
   private int triplestoreMaxConcurrent;
 
+  @Value("${" + TRIPLESTORE_ASYNC_CONSUMER + ":false}")
+  private boolean triplestoreAsyncConsumer;
+
   /**
    * Defines that triplestore indexer is only enabled if the appropriate property is set to "true".
    */
@@ -99,7 +103,7 @@ public String getTriplestoreBaseUrl() {
    *   The altered topic/queue string.
    */
   private String addConcurrent(final String queueString) {
-    return addJmsOptions(queueString, triplestoreConcurrent, triplestoreMaxConcurrent);
+    return addJmsOptions(queueString, triplestoreConcurrent, triplestoreMaxConcurrent, triplestoreAsyncConsumer);
   }
 
   /**

islandora-support/src/main/java/ca/islandora/alpaca/support/config/PropertyConfig.java

@@ -60,11 +60,15 @@ public int getMaxRedeliveries() {
    *   The number of concurrent consumers. -1 means no setting.
    * @param maxConcurrentConsumers
    *   The max number of concurrent consumers. -1 means no setting.
+   * @param asyncConsumers
+   *   Indicate if the queue should be processed strictly queue-wise (false;
+   *   more for dealing with overhead?); otherwise, allow multiple items to be
+   *   processed at the same time.
    * @return
    *   The modified topic/queue string.
    */
   public static String addJmsOptions(final String queueString, final int concurrentConsumers,
-                              final int maxConcurrentConsumers) {
+                              final int maxConcurrentConsumers, final boolean asyncConsumers) {
     final StringBuilder builder = new StringBuilder();
     if (concurrentConsumers > 0) {
       builder.append("concurrentConsumers=");
@@ -77,6 +81,13 @@ public static String addJmsOptions(final String queueString, final int concurren
       builder.append("maxConcurrentConsumers=");
       builder.append(maxConcurrentConsumers);
     }
+    if (asyncConsumers) {
+      if (builder.length() > 0) {
+        builder.append('&');
+      }
+      builder.append("asyncConsumer=")
+        .append(asyncConsumers);
+    }
     if (builder.length() > 0) {
       return queueString + (queueString.contains("?") ? '&' : '?') + builder;
     }