zhihai xu created YARN-3023:
-------------------------------
Summary: Race condition in ZKRMStateStore#createWithRetries from
ZooKeeper cause RM crash
Key: YARN-3023
URL: https://issues.apache.org/jira/browse/YARN-3023
Project: Hadoop YARN
Issue Type: Bug
Components: resourcemanager
Affects Versions: 2.6.0
Reporter: zhihai xu
Assignee: zhihai xu
Race condition in ZKRMStateStore#createWithRetries from ZooKeeper cause RM
crash.
The sequence for the Race condition is the following:
1, RM Store attempt state to ZK by calling createWithRetries
{code}
2015-01-06 12:37:35,343 INFO
org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.RMAppAttemptImpl:
Storing attempt: AppId: application_1418914202950_42363 AttemptId:
appattempt_1418914202950_42363_000001 MasterContainer: Container: [ContainerId:
container_1418914202950_42363_01_000001,
{code}
2. unluckily ConnectionLoss for the ZK session happened at the same time as RM
Stored attempt state to ZK.
The ZooKeeper server created the node and store the data successfully, But due
to ConnectionLoss, RM didn't know the operation (createWithRetries) is
succeeded.
{code}
2015-01-06 12:37:36,102 INFO
org.apache.hadoop.yarn.server.resourcemanager.recovery.ZKRMStateStore:
Exception while executing a ZK operation.
org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode =
ConnectionLoss
{code}
3.RM did retry to store attempt state to ZK after one second
{code}
2015-01-06 12:37:36,104 INFO
org.apache.hadoop.yarn.server.resourcemanager.recovery.ZKRMStateStore: Retrying
operation on ZK. Retry no. 1
{code}
4. during the one second interval, the ZK session is reconnected.
{code}
2015-01-06 12:37:36,210 INFO org.apache.zookeeper.ClientCnxn: Socket connection
established initiating session
2015-01-06 12:37:36,213 INFO org.apache.zookeeper.ClientCnxn: Session
establishment complete on server, sessionid = 0x44a9166eb2d12cb, negotiated
timeout = 10000
{code}
5. Because the node was created successfully at ZooKeeper in the first
try(runWithCheck),
For the second try, it will fail with NodeExists KeeperException
{code}
2015-01-06 12:37:37,116 INFO
org.apache.hadoop.yarn.server.resourcemanager.recovery.ZKRMStateStore:
Exception while executing a ZK operation.
org.apache.zookeeper.KeeperException$NodeExistsException: KeeperErrorCode =
NodeExists
2015-01-06 12:37:37,118 INFO
org.apache.hadoop.yarn.server.resourcemanager.recovery.ZKRMStateStore: Maxed
out ZK retries. Giving up!
{code}
6.This NodeExists KeeperException will cause Storing AppAttempt failure in
RMStateStore
{code}
2015-01-06 12:37:37,118 ERROR
org.apache.hadoop.yarn.server.resourcemanager.recovery.RMStateStore: Error
storing appAttempt: appattempt_1418914202950_42363_000001
org.apache.zookeeper.KeeperException$NodeExistsException: KeeperErrorCode =
NodeExists
{code}
7.RMStateStore will send RMFatalEventType.STATE_STORE_OP_FAILED event to
ResourceManager
{code}
protected void notifyStoreOperationFailed(Exception failureCause) {
RMFatalEventType type;
if (failureCause instanceof StoreFencedException) {
type = RMFatalEventType.STATE_STORE_FENCED;
} else {
type = RMFatalEventType.STATE_STORE_OP_FAILED;
}
rmDispatcher.getEventHandler().handle(new RMFatalEvent(type, failureCause));
}
{code}
8.ResoureManager will kill itself after received STATE_STORE_OP_FAILED
RMFatalEvent.
{code}
2015-01-06 12:37:37,128 FATAL
org.apache.hadoop.yarn.server.resourcemanager.ResourceManager: Received a
org.apache.hadoop.yarn.server.resourcemanager.RMFatalEvent of type
STATE_STORE_OP_FAILED. Cause:
org.apache.zookeeper.KeeperException$NodeExistsException: KeeperErrorCode =
NodeExists
2015-01-06 12:37:37,138 INFO org.apache.hadoop.util.ExitUtil: Exiting with
status 1
{code}
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