I try to configure ActiveMQ for the following behavior: when broker exceeds its memory limit, it should store message in persistence storage. If use the following configuration:
BrokerService broker = new BrokerService();
broker.setBrokerName("activemq");
KahaDBPersistenceAdapter persistence = new KahaDBPersistenceAdapter();
persistence.setDirectory(new File(config.getProperty("amq.persistenceDir", "amq")));
broker.setPersistenceAdapter(persistence);
broker.setVmConnectorURI(new URI("vm://activemq"));
broker.getSystemUsage().getMemoryUsage().setLimit(64 * 1024 * 1024L);
broker.getSystemUsage().getStoreUsage().setLimit(1024 * 1024 * 1024 * 100L);
broker.getSystemUsage().getTempUsage().setLimit(1024 * 1024 * 1024 * 100L);
PolicyEntry policyEntry = new PolicyEntry();
policyEntry.setCursorMemoryHighWaterMark(50);
policyEntry.setExpireMessagesPeriod(0L);
policyEntry.setPendingDurableSubscriberPolicy(new StorePendingDurableSubscriberMessageStoragePolicy());
policyEntry.setMemoryLimit(64 * 1024 * 1024L);
policyEntry.setProducerFlowControl(false);
broker.setDestinationPolicy(new PolicyMap());
broker.getDestinationPolicy().setDefaultEntry(policyEntry);
broker.setUseJmx(true);
broker.setPersistent(true);
broker.start();
However, this does not work. ActiveMQ still consumes as much memory as needed to store the full queue. I also tried to remove PolicyEntry, that caused broker to stop producers after memory limit is reached. I could find nothing in documentation about what I am doing wrong.