Revision 7343
Added by Chris Jones over 12 years ago
| src/edu/ucsb/nceas/metacat/dataone/hazelcast/HazelcastService.java | ||
|---|---|---|
| 49 | 49 |
import com.hazelcast.core.EntryListener; |
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import com.hazelcast.core.Hazelcast; |
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import com.hazelcast.core.HazelcastInstance; |
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import com.hazelcast.core.ILock; |
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import com.hazelcast.core.IMap; |
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import com.hazelcast.core.ISet; |
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import com.hazelcast.core.ItemListener; |
| ... | ... | |
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private static final String SINCE_PROPERTY = "dateSysMetadataModified"; |
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private static final String MISSING_PID_PREFIX = "missing-"; |
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/* The instance of the logging class */ |
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private static Logger logMetacat = Logger.getLogger(HazelcastService.class); |
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|
| ... | ... | |
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return pids; |
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} |
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/** |
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* Respond to itemAdded events on the hzMissingIdentifiers Set. Uses a |
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* distributed ILock to try to prevent multiple put calls on hzSystemMetadata |
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* |
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* @param pid the identifier of the event |
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*/ |
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@Override |
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public void itemAdded(Identifier pid) {
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// publish the SM for the pid if we have it locally |
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logMetacat.debug("Responding to itemAdded for pid: " + pid.getValue());
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ILock lock = null; |
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try {
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// look up the local copy of the SM |
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SystemMetadata sm = IdentifierManager.getInstance().getSystemMetadata(pid.getValue()); |
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if (sm != null) {
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// "publish" the system metadata to the shared map since it showed up on the missing queue |
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logMetacat.debug("Adding SystemMetadata to shared map for pid: " + pid.getValue());
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systemMetadata.put(pid, sm); |
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// remove the entry since we processed it |
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missingIdentifiers.remove(pid); |
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} else {
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logMetacat.warn("Local SystemMetadata was null for pid: " + pid.getValue());
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} |
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lock = hzInstance.getLock(MISSING_PID_PREFIX + pid.getValue()); |
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if ( lock.tryLock() ) {
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// look up the local copy of the SM |
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SystemMetadata sm = IdentifierManager.getInstance().getSystemMetadata(pid.getValue()); |
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if (sm != null) {
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// "publish" the system metadata to the shared map since it showed up on the missing queue |
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logMetacat.debug("Adding SystemMetadata to shared map for pid: " + pid.getValue());
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systemMetadata.put(pid, sm); |
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// remove the entry since we processed it |
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missingIdentifiers.remove(pid); |
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} else {
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logMetacat.warn("Local SystemMetadata was null for pid: " + pid.getValue());
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} |
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} else {
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logMetacat.debug(MISSING_PID_PREFIX + pid.getValue() + " was already locked. Skipping."); |
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} |
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} catch (Exception e) {
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logMetacat.error("Error looking up missing system metadata for pid: " + pid.getValue());
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} finally {
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if ( lock != null ) {
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lock.unlock(); |
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} |
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} |
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} |
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/** |
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* Respond to itemRemoved events on the hzMissingIdentifiers Set |
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* |
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* @param pid the identifier of the event |
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*/ |
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@Override |
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public void itemRemoved(Identifier arg0) {
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public void itemRemoved(Identifier pid) {
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// do nothing since someone probably handled the wanted PID |
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|
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} |
Also available in: Unified diff
Add locking to the itemAdded() method so ideally only one CN will respond to the request for a 'wanted' pid from the cluster. The lock is on a string, not the pid, and so won't conflict with system metadata locking. The string is based on the pid, with "missing-" as a prefix.