Github user keith-turner commented on a diff in the pull request:
https://github.com/apache/accumulo/pull/107#discussion_r65650715
--- Diff:
server/gc/src/main/java/org/apache/accumulo/gc/GarbageCollectWriteAheadLogs.java
---
@@ -170,76 +184,203 @@ boolean holdsLock(HostAndPort addr) {
}
}
- private int removeFiles(Map<String,Path> nameToFileMap,
Map<String,ArrayList<Path>> serverToFileMap, Map<String,Path> sortedWALogs,
final GCStatus status) {
- AccumuloConfiguration conf =
ServerConfiguration.getSystemConfiguration(instance);
+ private AccumuloConfiguration getConfig() {
+ return ServerConfiguration.getSystemConfiguration(instance);
+ }
+
+ /**
+ * Top level method for removing WAL files.
+ * <p>
+ * Loops over all the gathered WAL and sortedWAL entries and calls the
appropriate methods for removal
+ *
+ * @param nameToFileMap
+ * Map of filename to Path
+ * @param serverToFileMap
+ * Map of HostAndPort string to a list of Paths
+ * @param sortedWALogs
+ * Map of sorted WAL names to Path
+ * @param status
+ * GCStatus object for tracking what is done
+ * @return 0 always
+ */
+ @VisibleForTesting
+ int removeFiles(Map<String,Path> nameToFileMap,
Map<String,ArrayList<Path>> serverToFileMap, Map<String,Path> sortedWALogs,
final GCStatus status) {
+ // TODO: remove nameToFileMap from method signature, not used here I
don't think
+ AccumuloConfiguration conf = getConfig();
for (Entry<String,ArrayList<Path>> entry : serverToFileMap.entrySet())
{
if (entry.getKey().isEmpty()) {
- // old-style log entry, just remove it
- for (Path path : entry.getValue()) {
- log.debug("Removing old-style WAL " + path);
- try {
- if (!useTrash || !fs.moveToTrash(path))
- fs.deleteRecursively(path);
- status.currentLog.deleted++;
- } catch (FileNotFoundException ex) {
- // ignored
- } catch (IOException ex) {
- log.error("Unable to delete wal " + path + ": " + ex);
- }
- }
+ removeOldStyleWAL(entry, status);
} else {
- HostAndPort address = AddressUtil.parseAddress(entry.getKey(),
false);
- if (!holdsLock(address)) {
- for (Path path : entry.getValue()) {
- log.debug("Removing WAL for offline server " + path);
- try {
- if (!useTrash || !fs.moveToTrash(path))
- fs.deleteRecursively(path);
- status.currentLog.deleted++;
- } catch (FileNotFoundException ex) {
- // ignored
- } catch (IOException ex) {
- log.error("Unable to delete wal " + path + ": " + ex);
- }
- }
- continue;
- } else {
- Client tserver = null;
- try {
- tserver = ThriftUtil.getClient(new
TabletClientService.Client.Factory(), address, conf);
- tserver.removeLogs(Tracer.traceInfo(),
SystemCredentials.get().toThrift(instance), paths2strings(entry.getValue()));
- log.debug("deleted " + entry.getValue() + " from " +
entry.getKey());
- status.currentLog.deleted += entry.getValue().size();
- } catch (TException e) {
- log.warn("Error talking to " + address + ": " + e);
- } finally {
- if (tserver != null)
- ThriftUtil.returnClient(tserver);
- }
- }
+ removeWALFile(entry, conf, status);
}
}
-
for (Path swalog : sortedWALogs.values()) {
- log.debug("Removing sorted WAL " + swalog);
+ removeSortedWAL(swalog);
+ }
+ return 0;
+ }
+
+ /**
+ * Removes sortedWALs.
+ * <p>
+ * Sorted WALs are WALs that are in the recovery directory and have
already been used.
+ *
+ * @param swalog
+ * Path to the WAL
+ */
+ @VisibleForTesting
+ void removeSortedWAL(Path swalog) {
+ log.debug("Removing sorted WAL " + swalog);
+ try {
+ if (!useTrash || !fs.moveToTrash(swalog)) {
+ fs.deleteRecursively(swalog);
+ }
+ } catch (FileNotFoundException ex) {
+ // ignored
+ } catch (IOException ioe) {
try {
- if (!useTrash || !fs.moveToTrash(swalog)) {
- fs.deleteRecursively(swalog);
+ if (fs.exists(swalog)) {
+ log.error("Unable to delete sorted walog " + swalog + ": " +
ioe);
}
- } catch (FileNotFoundException ex) {
- // ignored
- } catch (IOException ioe) {
+ } catch (IOException ex) {
+ log.error("Unable to check for the existence of " + swalog, ex);
+ }
+ }
+ }
+
+ /**
+ * A wrapper method to check if the tserver using the WAL is still alive
+ * <p>
+ * Delegates to the deletion to #removeWALfromDownTserver if the ZK lock
is gone or #askTserverToRemoveWAL if the server is known to still be alive
+ *
+ * @param entry
+ * WAL information gathered
+ * @param conf
+ * AccumuloConfiguration object
+ * @param status
+ * GCStatus object
+ */
+ @VisibleForTesting
+ void removeWALFile(Entry<String,ArrayList<Path>> entry,
AccumuloConfiguration conf, final GCStatus status) {
+ HostAndPort address = AddressUtil.parseAddress(entry.getKey(), false);
+ if (!holdsLock(address)) {
+ removeWALfromDownTserver(address, conf, entry, status);
+ } else {
+ askTserverToRemoveWAL(address, conf, entry, status);
+ }
+ }
+
+ /**
+ * Asks a currently running tserver to remove it's WALs.
+ * <p>
+ * A tserver has more information about whether a WAL is still being
used for current mutations. It is safer to ask the tserver to remove the file
instead of
+ * just relying on information in the metadata table.
+ *
+ * @param address
+ * HostAndPort of the tserver
+ * @param conf
+ * AccumuloConfiguration entry
+ * @param entry
+ * WAL information gathered
+ * @param status
+ * GCStatus object
+ */
+ @VisibleForTesting
+ void askTserverToRemoveWAL(HostAndPort address, AccumuloConfiguration
conf, Entry<String,ArrayList<Path>> entry, final GCStatus status) {
+ firstSeenDead.remove(address);
+ Client tserver = null;
+ try {
+ tserver = ThriftUtil.getClient(new
TabletClientService.Client.Factory(), address, conf);
+ tserver.removeLogs(Tracer.traceInfo(),
SystemCredentials.get().toThrift(instance), paths2strings(entry.getValue()));
+ log.debug("asking tserver to delete " + entry.getValue() + " from "
+ entry.getKey());
--- End diff --
I think it should say `asked` instead of `asking` because the log message
is after the thrift call.
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