Updated Branches: refs/heads/trunk be2726b39 -> f70339682
more comment update Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/f7033968 Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/f7033968 Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/f7033968 Branch: refs/heads/trunk Commit: f70339682524026a3955bf56ac7a0d4f4f1e1114 Parents: be2726b Author: Yuki Morishita <yu...@apache.org> Authored: Thu Mar 28 23:28:05 2013 -0500 Committer: Yuki Morishita <yu...@apache.org> Committed: Thu Mar 28 23:29:06 2013 -0500 ---------------------------------------------------------------------- .../cassandra/service/ActiveRepairService.java | 54 +++++---------- 1 files changed, 18 insertions(+), 36 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/cassandra/blob/f7033968/src/java/org/apache/cassandra/service/ActiveRepairService.java ---------------------------------------------------------------------- diff --git a/src/java/org/apache/cassandra/service/ActiveRepairService.java b/src/java/org/apache/cassandra/service/ActiveRepairService.java index 3c5ba7f..f103771 100644 --- a/src/java/org/apache/cassandra/service/ActiveRepairService.java +++ b/src/java/org/apache/cassandra/service/ActiveRepairService.java @@ -51,34 +51,30 @@ import org.apache.cassandra.utils.*; /** * ActiveRepairService encapsulates "validating" (hashing) individual column families, - * exchanging MerkleTrees with remote nodes via a TreeRequest/Response conversation, + * exchanging MerkleTrees with remote nodes via a tree request/response conversation, * and then triggering repairs for disagreeing ranges. * * The node where repair was invoked acts as the 'initiator,' where valid trees are sent after generation - * and where the local and remote tree will rendezvous in rendezvous(cf, endpoint, tree). + * and where the local and remote tree will rendezvous in rendezvous(). * Once the trees rendezvous, a Differencer is executed and the service can trigger repairs * for disagreeing ranges. * - * Tree comparison and repair triggering occur in the single threaded Stage.ANTIENTROPY. + * Tree comparison and repair triggering occur in the single threaded Stage.ANTI_ENTROPY. * * The steps taken to enact a repair are as follows: - * 1. A repair is requested via nodeprobe: + * 1. A repair is requested via JMX/nodetool: * * The initiator sends TreeRequest messages to all neighbors of the target node: when a node * receives a TreeRequest, it will perform a validation (read-only) compaction to immediately validate * the column family. This is performed on the CompactionManager ExecutorService. * 2. The validation process builds the merkle tree by: * * Calling Validator.prepare(), which samples the column family to determine key distribution, - * * Calling Validator.add() in order for every row in the column family, + * * Calling Validator.add() in order for rows in repair range in the column family, * * Calling Validator.complete() to indicate that all rows have been added. * * Calling complete() indicates that a valid MerkleTree has been created for the column family. * * The valid tree is returned to the requesting node via a TreeResponse. - * 3. When a node receives a TreeResponse, it passes the tree to rendezvous(), which checks for trees to - * rendezvous with / compare to: - * * If the tree is local, it is cached, and compared to any trees that were received from neighbors. - * * If the tree is remote, it is immediately compared to a local tree if one is cached. Otherwise, - * the remote tree is stored until a local tree can be generated. - * * A Differencer object is enqueued for each comparison. - * 4. Differencers are executed in Stage.ANTIENTROPY, to compare the two trees, and perform repair via the + * 3. When a node receives a tree response, it passes the tree to rendezvous() to see if all responses are + * received. Once the initiator receives all responses, it creates Differencers on every tree pair combination. + * 4. Differencers are executed in Stage.ANTI_ENTROPY, to compare the given two trees, and perform repair via the * streaming api. */ public class ActiveRepairService @@ -110,7 +106,7 @@ public class ActiveRepairService private final ConcurrentMap<String, RepairSession> sessions; /** - * Protected constructor. Use AntiEntropyService.instance. + * Protected constructor. Use ActiveRepairService.instance. */ protected ActiveRepairService() { @@ -118,7 +114,7 @@ public class ActiveRepairService } /** - * Requests repairs for the given table and column families, and blocks until all repairs have been completed. + * Requests repairs for the given keyspace and column families. * * @return Future for asynchronous call or null if there is no need to repair */ @@ -252,12 +248,12 @@ public class ActiveRepairService } /** - * A Strategy to handle building and validating a merkle tree for a column family. + * A Strategy to handle building a merkle tree for a column family. * * Lifecycle: * 1. prepare() - Initialize tree with samples. * 2. add() - 0 or more times, to add hashes to the tree. - * 3. complete() - Enqueues any operations that were blocked waiting for a valid tree. + * 3. complete() - complete building tree and send it back to the initiator */ public static class Validator implements Runnable { @@ -332,21 +328,9 @@ public class ActiveRepairService } /** - * Called (in order) for every row present in the CF. + * Called (in order) for rows in given range present in the CF. * Hashes the row, and adds it to the tree being built. * - * There are four possible cases: - * 1. Token is greater than range.right (we haven't generated a range for it yet), - * 2. Token is less than/equal to range.left (the range was valid), - * 3. Token is contained in the range (the range is in progress), - * 4. No more invalid ranges exist. - * - * TODO: Because we only validate completely empty trees at the moment, we - * do not bother dealing with case 2 and case 4 should result in an error. - * - * Additionally, there is a special case for the minimum token, because - * although it sorts first, it is contained in the last possible range. - * * @param row The row. */ public void add(AbstractCompactedRow row) @@ -381,7 +365,7 @@ public class ActiveRepairService } /** - * Registers the newly created tree for rendezvous in Stage.ANTIENTROPY. + * Registers the newly created tree for rendezvous in Stage.ANTI_ENTROPY. */ public void complete() { @@ -405,7 +389,7 @@ public class ActiveRepairService } /** - * Called after the validation lifecycle to respond with the now valid tree. Runs in Stage.ANTIENTROPY. + * Called after the validation lifecycle to respond with the now valid tree. Runs in Stage.ANTI_ENTROPY. */ public void run() { @@ -449,7 +433,6 @@ public class ActiveRepairService /** * Handler for requests from remote nodes to generate a valid tree. - * The payload is a CFPair representing the columnfamily to validate. */ public static class TreeRequestVerbHandler implements IVerbHandler<TreeRequest> { @@ -578,7 +561,6 @@ public class ActiveRepairService /** * Triggers repairs with all neighbors for the given table, cfs and range. - * Typical lifecycle is: start() then join(). Executed in client threads. */ static class RepairSession extends WrappedRunnable implements IEndpointStateChangeSubscriber, IFailureDetectionEventListener { @@ -718,7 +700,7 @@ public class ActiveRepairService } /** - * @return wheather this session is terminated + * @return whether this session is terminated */ public boolean terminated() { @@ -735,7 +717,7 @@ public class ActiveRepairService } /** - * clear all RepairJobs and terminate this session. + * terminate this session. */ public void forceShutdown() { @@ -933,7 +915,7 @@ public class ActiveRepairService } /** - * @return true if the @param differencer was the last remaining + * @return true if the differencer was the last remaining */ synchronized boolean completedSynchronization(Differencer differencer) {
