RE: Extra classpath entries
Kyle, This is exactly what I need. Thanks! I checked jira before asking the email list but I guess I missed that entry somehow. My bad. Date: Thu, 24 Jul 2014 17:41:37 -0500 From: knusb...@yahoo-inc.com To: user@storm.incubator.apache.org; michael_...@outlook.com Subject: Re: Extra classpath entries Hi, Michael. I'm not sure what version of storm you are using, but the TOPOLOGY_CLASSPATH and TOPOLOGY_ENVIRONMENT config variables that were recently added look like they might work for you. https://issues.apache.org/jira/browse/STORM-54 -- Kyle On 07/24/2014 03:15 PM, Michael Dev wrote: Is there a way to provide extra classpath entries for the worker jvms when using the storm script? I see that storm.cmd utilizes the STORM_CLASSPATH environment variable yet the python script does not provide any such capability. Our reasoning behind wanting this is the nature of our production environment makes recompiling and redeploying the jar with dependencies difficult. In most situations we only need to modify a config property so we'd much prefer to utilize an external config directory shared across storm nodes on the classpath than have to recompile and redeploy the jar with deps. Additionally in our scenario we have to share some configs with code external to our topologies (things like db connection info, etc) so it'd make way more sense to reference those configs in one location. Thanks, Michael
RE: Workers constantly restarted due to session timeout
Thanks again for all the advice. Turns out the issue was related to GC. The long pauses in uptime were directly correlated to full GC executions pausing all threads. We had written a spout that was caching input tuples locally waiting for the cluster to invoke ISpout.nextTuple(). The topology just wasn't operating fast enough so that spout's local cache would grow unbounded resulting in hitting very high memory usage (up to whatever xmx was, 30, 60, 100gb) thus resulting in painfully long stop-theworld GC executions. We were falling short of being able to handle the spout's activity by around 100-200k tuples every 30 seconds. Unfortunately this indicates that we'll need to reevaluate inefficient sections in our topology barring more hardware but at least the issue as been identified. Thanks, Michael Date: Tue, 3 Jun 2014 14:06:38 -0500 From: der...@yahoo-inc.com To: user@storm.incubator.apache.org Subject: Re: Workers constantly restarted due to session timeout 1) Is it appropriate to run Zookeeper in parallel on the same node with the storm services? I recommend separate, and even then to ZK storage to a path on its own disk device if possible. ZK is a bottleneck for storm, and when it is too slow lots of bad things can happen. Some folks use shared hosts (with or without VMs) in which to run ZK. In those situations, VMs or processes owned by other users doing unrelated things can put load on the disk, and that will dramatically slow down ZK. 2) We have zookeeper 3.4.5 installed. I see Storm uses zookeeper-3.3.3 as its client. Should we downgrade our installation? I am not sure about that, since we've been running with ZK 3.4.5 in storm (and on the server). It might work very well, but I have not tried it. I do not remember if anyone on this list has identified any issues with this 3.3.3 + 3.4.5 combo. One setting we changed to dramatically improve performance with ZK was setting the system property '-Dzookeeper.forceSync=no' on the server. Normally, ZK will sync to disk on every write, and that causes two seeks: one for the data and one for the data log. It gets really expensive with all of the workers heartbeating in through ZK. Be warned that with only on ZK server, an outage could leave you in an inconsistent state. You might check to see if the ZK server is keeping up. There are tools like iotop that can give information about disk load. -- Derek On 6/3/14, 13:14, Michael Dev wrote: Thank you Derek for the explanation between :disallowed and :timed-out. That was extremely helpful in understanding what decisions Storm is making. I increased the timeouts for both messages to 5 minutes and returned the zookeeper session timeouts to their default values. This made it plain to see periods in time where the Uptime column for the busiest component's Worker would not update (1-2 minutes, potentially never resulting in a worker restart). ZK logs report constant disconnects and reconnects while the Uptime is not updating: 16:28:30,440 - INFO NIOServerCnxn@1001 - Closed socket connection for client /10.49.21.151:54004 which has sessionid 0x1464f1fddc1018f 16:31:18,364 - INFO NIOServerCnxnFactory@197 - Accepted socket connection from /10.49.21.151:34419 16.31:18,365 - WARN ZookeeperServer@793 - Connection request from old client /10.49.21.151:34419; will be dropped if server is in r-o mode 16:31:18,365 - INFO ZookeeperServer@832 - Client attempting to renew session 0x264f1fddc4021e at /10.49.21.151:34419 16:31:18,365 - INFO Learner@107 - Revalidating client: 0x264f1fddc4021e 16:31:18,366 - INFO ZooKeeperServer@588 - Invalid session 0x264f1fddc4021e for client /10.49.21.151:34419, probably expired 16:31:18,366 - NIOServerCnxn@1001 - Closed socket connection for client /10.49.21.151:34419 which had sessionid 0x264f1fddc4021e 16:31:18,378 - INFO NIOServerCnxnFactory@197 - Accepted socket connection from /10.49.21.151:34420 16:31:18,391 - WARN ZookeeperServer@793 - Connection request from old client /10.49.21.151:34420; will be dropped if server is in r-o mode 16:31:18,392 - INFO ZookeeperServer@839 - Client attempting to establish new session at /10.49.21.151:34420 16:31:18,394 - INFO ZookeeperServer@595 - Established session 0x1464fafddc10218 with negotiated timeout 2 for client /10.49.21.151:34420 16.31.44,002 - INFO NIOServerCnxn@1001 - Closed socket connection for /10.49.21.151:34420 which had sessionid 0x1464fafddc10218 16.32.48,055 - INFO NIOServerCxnFactory@197 - Accepted socket connection from /10.49.21.151:34432 16:32:48,056 - WARN ZookeeperServer@793 - Connection request from old client /10.49.21.151:34432; will be dropped if server is in r-o mode 16.32.48,056 - INFO ZookeeperServer@832 - Client attempting to renew session 0x2464fafddc4021f at /10.49.21.151:34432 16:32:48,056 - INFO Learner@107
RE: Workers constantly restarted due to session timeout
was high enough to prevent heartbeats, then I would expect to see :timed-out state above instead of :disallowed. The reason is that the worker has only 5 seconds to do those heartbeats, while it has 30 seconds to heartbeat to nimbus (via ZK). (More often what happens to cause this is memory has run out and garbage collection stops everything just long enough.) The real question is why connections from the worker to ZK are timing out in the first place. What about the ZK servers? Sometimes ZooKeeper servers cannot keep up, and that causes pretty severe problems with timeouts. -- Derek On 5/30/14, 17:51, Michael Dev wrote: Michael R, We don't have GC logging enabled yet. I lean towards agreeing with Derek that I don't think it's the issue but I will take a look at logging on Monday just to verify. Derek D, Are you certain that nimbus.task.timeout.secs is the correct config? Tracing through the github code it would seem to me that this is used as the timeout value when making a Thrift connection to the Nimbus node. I thought the logs indicated the timeout was occurring in the session connection to zookeeper as evidenced by ClientCxn being a Zookeeper class. I discovered that we were running with the default maxSessionTimeout zookeeper config of 40 seconds. This would explain why our storm config of 5 minutes was not being picked up (but obviously not the root problem nor why timeout messages report 14-20 second timeout values). Typically we saw losses in connection occur when our cluster becomes super busy with a burst of data pushing workers to near 100% CPU. I'm testing the following configs over the weekend to see if they at least allow us to prevent chronic worker restarting during the brief high CPU periods. Our current setup is as follows: Storm 0.9.0.1 3 Storm node cluster 1 Supervisor running per Storm node 1-3 topologies deployed on the Storm cluster (depends on dev/prod/etc systems) 3 Workers per topology Variable number of executors per component depending on how slow that component is. Example file i/o has many executors (say 12) while in memory validation has only 3 executors. Always maintaining a multiple of the number of workers for even distribution. Kyro serialization with Java Serialization failover disabled to ensure we're using 100% kryo between bolts. zoo.cfg tickTime=2000 dataDir=/srv/zookeeper/data clientPort=2182 initLimit=5 syncLimit=2 skipACL=true maxClientCnxns=1000 maxSessionTimeout=30 server.1=node1 server.2=node2 server.3=node3 storm yaml storm.zookeeper.port: 2182 storm.local.dir=/srv/storm/data nimbus.host: node1 storm.zookeeper.servers: - node1 - node2 - node3 supervisor.slot.ports: - 6700 - 6701 - 6702 - 6703 - 6704 java.library.path: /usr/lib:/srv/storm/lib #Storm 0.9 netty support storm.messaging.transport: backtype.storm.messaging.netty.Context storm.messaging.netty.server_worker_threads: 1 storm.messaging.netty.client_worker_threads: 1 storm.messaging.netty.buffer_size: 5242880 storm.messaging.netty.max_retries: 100 storm.messaging.netty.max_wait_ms: 1000 storm.messaging.netty.min_wait_ms: 100 # Timeout band-aids in testing topology.receiver.buffer.size: 2 storm.zookeeper.connection.timeout: 30 storm.zookeeper.session.timeout: 30 Date: Thu, 29 May 2014 12:56:19 -0500 From: der...@yahoo-inc.com To: user@storm.incubator.apache.org Subject: Re: Workers constantly restarted due to session timeout OK, so GC is probably not the issue. Specifically, this is a connection timeout to ZK from the worker, and it is resulting in nimbus removing it from the assignments for that node. In turn, the supervisor reads the schedule and shoots the worker because it is no longer scheduled to be running. The relevant config is nimbus.task.timeout.secs, and I think the default is 30s. What you could try is to make nimbus timeout longer than storm.zookeeper.session.timeout. This would allow the ZK connections to timeout and get a heartbeat in before nimbus decides they have timed out. But the real question is why are the ZK sessions timing out at all? Do you see this on several workers on that node? What about the supervisor? What about other nodes? What do the ZK logs say? -- Derek On 5/29/14, 11:45, Michael Dev wrote: Derek, We are currently running with -Xmx60G and only about 20-30G of that has been observed to be used. I'm still observing workers restarted every 2 minutes. What timeout is relevant to increase for the heartbeats in question? Is it be a config on the Zookeeper side we can increase to make our topology more resilient to these restarts? Michael Date: Fri, 23 May 2014 15:50:50 -0500 From: der...@yahoo-inc.com To: user
RE: Workers constantly restarted due to session timeout
Michael R, We don't have GC logging enabled yet. I lean towards agreeing with Derek that I don't think it's the issue but I will take a look at logging on Monday just to verify. Derek D, Are you certain that nimbus.task.timeout.secs is the correct config? Tracing through the github code it would seem to me that this is used as the timeout value when making a Thrift connection to the Nimbus node. I thought the logs indicated the timeout was occurring in the session connection to zookeeper as evidenced by ClientCxn being a Zookeeper class. I discovered that we were running with the default maxSessionTimeout zookeeper config of 40 seconds. This would explain why our storm config of 5 minutes was not being picked up (but obviously not the root problem nor why timeout messages report 14-20 second timeout values). Typically we saw losses in connection occur when our cluster becomes super busy with a burst of data pushing workers to near 100% CPU. I'm testing the following configs over the weekend to see if they at least allow us to prevent chronic worker restarting during the brief high CPU periods. Our current setup is as follows: Storm 0.9.0.1 3 Storm node cluster 1 Supervisor running per Storm node 1-3 topologies deployed on the Storm cluster (depends on dev/prod/etc systems) 3 Workers per topology Variable number of executors per component depending on how slow that component is. Example file i/o has many executors (say 12) while in memory validation has only 3 executors. Always maintaining a multiple of the number of workers for even distribution. Kyro serialization with Java Serialization failover disabled to ensure we're using 100% kryo between bolts. zoo.cfg tickTime=2000 dataDir=/srv/zookeeper/data clientPort=2182 initLimit=5 syncLimit=2 skipACL=true maxClientCnxns=1000 maxSessionTimeout=30 server.1=node1 server.2=node2 server.3=node3 storm yaml storm.zookeeper.port: 2182 storm.local.dir=/srv/storm/data nimbus.host: node1 storm.zookeeper.servers: - node1 - node2 - node3 supervisor.slot.ports: - 6700 - 6701 - 6702 - 6703 - 6704 java.library.path: /usr/lib:/srv/storm/lib #Storm 0.9 netty support storm.messaging.transport: backtype.storm.messaging.netty.Context storm.messaging.netty.server_worker_threads: 1 storm.messaging.netty.client_worker_threads: 1 storm.messaging.netty.buffer_size: 5242880 storm.messaging.netty.max_retries: 100 storm.messaging.netty.max_wait_ms: 1000 storm.messaging.netty.min_wait_ms: 100 # Timeout band-aids in testing topology.receiver.buffer.size: 2 storm.zookeeper.connection.timeout: 30 storm.zookeeper.session.timeout: 30 Date: Thu, 29 May 2014 12:56:19 -0500 From: der...@yahoo-inc.com To: user@storm.incubator.apache.org Subject: Re: Workers constantly restarted due to session timeout OK, so GC is probably not the issue. Specifically, this is a connection timeout to ZK from the worker, and it is resulting in nimbus removing it from the assignments for that node. In turn, the supervisor reads the schedule and shoots the worker because it is no longer scheduled to be running. The relevant config is nimbus.task.timeout.secs, and I think the default is 30s. What you could try is to make nimbus timeout longer than storm.zookeeper.session.timeout. This would allow the ZK connections to timeout and get a heartbeat in before nimbus decides they have timed out. But the real question is why are the ZK sessions timing out at all? Do you see this on several workers on that node? What about the supervisor? What about other nodes? What do the ZK logs say? -- Derek On 5/29/14, 11:45, Michael Dev wrote: Derek, We are currently running with -Xmx60G and only about 20-30G of that has been observed to be used. I'm still observing workers restarted every 2 minutes. What timeout is relevant to increase for the heartbeats in question? Is it be a config on the Zookeeper side we can increase to make our topology more resilient to these restarts? Michael Date: Fri, 23 May 2014 15:50:50 -0500 From: der...@yahoo-inc.com To: user@storm.incubator.apache.org Subject: Re: Workers constantly restarted due to session timeout 2) Is this expected behavior for Storm to be unable to keep up with heartbeat threads under high CPU or is our theory incorrect? Check your JVM max heap size (-Xmx). If you use too much, the JVM will garbage-collect, and that will stop everything--including the thread whose job it is to do the heartbeating. -- Derek On 5/23/14, 15:38, Michael Dev wrote: Hi all, We are seeing our workers constantly being killed by Storm with to the following logs: worker: 2014-05-23 20:15:08 INFO ClientCxn:1157 - Client session timed out, have not heard from the server in 28105ms for sessionid 0x14619bf2f4e0109, closing socket and attempting reconnect supervisor: 2014-05-23 20:17:30 INFO supervisor:0 - Shutting
RE: Workers constantly restarted due to session timeout
Derek,
We are currently running with -Xmx60G and only about 20-30G of that has been
observed to be used. I'm still observing workers restarted every 2 minutes.
What timeout is relevant to increase for the heartbeats in question? Is it be a
config on the Zookeeper side we can increase to make our topology more
resilient to these restarts?
Michael
Date: Fri, 23 May 2014 15:50:50 -0500
From: der...@yahoo-inc.com
To: user@storm.incubator.apache.org
Subject: Re: Workers constantly restarted due to session timeout
2) Is this expected behavior for Storm to be unable to keep up with
heartbeat threads under high CPU or is our theory incorrect?
Check your JVM max heap size (-Xmx). If you use too much, the JVM will
garbage-collect, and that will stop everything--including the thread whose
job it is to do the heartbeating.
--
Derek
On 5/23/14, 15:38, Michael Dev wrote:
Hi all,
We are seeing our workers constantly being killed by Storm with to the
following logs:
worker: 2014-05-23 20:15:08 INFO ClientCxn:1157 - Client session timed out,
have not heard from the server in 28105ms for sessionid 0x14619bf2f4e0109,
closing socket and attempting reconnect
supervisor: 2014-05-23 20:17:30 INFO supervisor:0 - Shutting down and
clearing state for id 94349373-74ec-484b-a9f8-a5076e17d474. Current
supervisor time: 1400876250. State: :disallowed, Heartbeat:
#backtype.storm.daemon.common.WorkerHeartbeat{{:time-secs 1400876249,
:storm-id test-46-1400863199, :executors #{[-1 -1]}, :port 6700}
Eventually Storm decides to just kill the worker and restart it as you see
in the supervisor log. We theorize this is the Zookeeper heartbeat thread
and it is being choked out due to very high CPU load on the machine (near
100%).
I have increased the connection timeouts in the storm.yaml config file yet
Storm seems to continue to use some unknown value for the above client
session timeout messages:
storm.zookeeper.connection.timeout: 30
storm.zookeeper.session.timeout: 30
1) What timeout config is appropriate for the above timeout message?
2) Is this expected behavior for Storm to be unable to keep up with
heartbeat threads under high CPU or is our theory incorrect?
Thanks,
Michael
Workers constantly restarted due to session timeout
Hi all,
We are seeing our workers constantly being killed by Storm with to the
following logs:
worker: 2014-05-23 20:15:08 INFO ClientCxn:1157 - Client session timed out,
have not heard from the server in 28105ms for sessionid 0x14619bf2f4e0109,
closing socket and attempting reconnect
supervisor: 2014-05-23 20:17:30 INFO supervisor:0 - Shutting down and clearing
state for id 94349373-74ec-484b-a9f8-a5076e17d474. Current supervisor time:
1400876250. State: :disallowed, Heartbeat:
#backtype.storm.daemon.common.WorkerHeartbeat{{:time-secs 1400876249, :storm-id
test-46-1400863199, :executors #{[-1 -1]}, :port 6700}
Eventually Storm decides to just kill the worker and restart it as you see in
the supervisor log. We theorize this is the Zookeeper heartbeat thread and it
is being choked out due to very high CPU load on the machine (near 100%).
I have increased the connection timeouts in the storm.yaml config file yet
Storm seems to continue to use some unknown value for the above client session
timeout messages:
storm.zookeeper.connection.timeout: 30
storm.zookeeper.session.timeout: 30
1) What timeout config is appropriate for the above timeout message?
2) Is this expected behavior for Storm to be unable to keep up with heartbeat
threads under high CPU or is our theory incorrect?
Thanks,
Michael
