Re: JobManager refusing connections when running many jobs in parallel?

Posted by rmetzger0 on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/JobManager-refusing-connections-when-running-many-jobs-in-parallel-tp36985p37027.html

Hi Andreas,

Thanks for reaching out .. this should not happen ...
Maybe your operating system has configured low limits for the number of concurrent connections / sockets. Maybe this thread is helpful: https://stackoverflow.com/questions/923990/why-do-i-get-connection-refused-after-1024-connections (there might better SO threads, I didn't put much effort into searching :) )

On Mon, Jul 27, 2020 at 6:31 PM Hailu, Andreas <[hidden email]> wrote:

Hi team,

 

We’ve observed that when we submit a decent number of jobs in parallel from a single Job Master, we encounter job failures due with Connection Refused exceptions. We’ve seen this behavior start at 30 jobs running in parallel. It’s seemingly transient, however, as upon several retries the job succeeds. The surface level error varies, but digging deeper in stack traces it looks to stem from the Job Manager no longer accepting connections.

 

I’ve included a couple of examples below from failed jobs’ driver logs, with different errors stemming from a connection refused error:

 

First example: 15 Task Managers/2 cores/4096 Job Manager memory/12288 Task Manager memory - 30 jobs submitted in parallel, each with parallelism of 1

Job Manager is running @ d43723-563.dc.gs.com: Using job manager web tracking url <a href="http://d43723-563.dc.gs.com:41268"> Job Manager Web Interface  (http://d43723-563.dc.gs.com:41268) </a>

org.apache.flink.client.program.ProgramInvocationException: Could not retrieve the execution result. (JobID: 1dfef6303cf0e888231d4c57b4b4e0e6)

at org.apache.flink.client.program.rest.RestClusterClient.submitJob(RestClusterClient.java:255)

at org.apache.flink.client.program.ClusterClient.run(ClusterClient.java:338)

at org.apache.flink.client.program.ClusterClient.run(ClusterClient.java:326)

at org.apache.flink.client.program.ContextEnvironment.execute(ContextEnvironment.java:62)

...

Caused by: org.apache.flink.runtime.concurrent.FutureUtils$RetryException: Could not complete the operation. Number of retries has been exhausted.

at org.apache.flink.runtime.concurrent.FutureUtils.lambda$retryOperationWithDelay$8(FutureUtils.java:273)

at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)

at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736)

at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)

at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1977)

at org.apache.flink.runtime.rest.RestClient.lambda$submitRequest$1(RestClient.java:341)

at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:511)

at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.notifyListeners0(DefaultPromise.java:504)

at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:483)

at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:424)

at org.apache.flink.shaded.netty4.io.netty.util.concurrent.DefaultPromise.tryFailure(DefaultPromise.java:121)

at org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.fulfillConnectPromise(AbstractNioChannel.java:327)

at org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:343)

at org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:644)

at org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:591)

at org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:508)

at org.apache.flink.shaded.netty4.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:470)

at org.apache.flink.shaded.netty4.io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:909)

... 1 more

Caused by: java.util.concurrent.CompletionException: org.apache.flink.shaded.netty4.io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: d43723-563.dc.gs.com/10.47.126.221:41268

at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:292)

at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:308)

at java.util.concurrent.CompletableFuture.uniCompose(CompletableFuture.java:943)

at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:926)

... 16 more

Caused by: org.apache.flink.shaded.netty4.io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: d43723-563.dc.gs.com/10.47.126.221:41268

at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)

at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)

at org.apache.flink.shaded.netty4.io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:327)

at org.apache.flink.shaded.netty4.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:340)

... 6 more

Caused by: java.net.ConnectException: Connection refused

 

Second example: 30 Task Managers/2 cores/4096 Job Manager memory/12288 Task Manager memory - 60 jobs submitted in parallel, each with parallelism of 1

Job Manager is running @ d43723-484.dc.gs.com: Using job manager web tracking url <a href="http://d43723-484.dc.gs.com:36757"> Job Manager Web Interface  (http://d43723-484.dc.gs.com:36757) </a>

org.apache.flink.client.program.ProgramInvocationException: Could not retrieve the execution result. (JobID: 9c4a797df26b510a92a843c756dc4b3d)

at org.apache.flink.client.program.rest.RestClusterClient.submitJob(RestClusterClient.java:255)

at org.apache.flink.client.program.ClusterClient.run(ClusterClient.java:338)

at org.apache.flink.client.program.ClusterClient.run(ClusterClient.java:326)

at org.apache.flink.client.program.ContextEnvironment.execute(ContextEnvironment.java:62)

...

Caused by: org.apache.flink.runtime.client.JobSubmissionException: Failed to submit JobGraph.

at org.apache.flink.client.program.rest.RestClusterClient.lambda$submitJob$8(RestClusterClient.java:382)

at java.util.concurrent.CompletableFuture.uniExceptionally(CompletableFuture.java:870)

at java.util.concurrent.CompletableFuture$UniExceptionally.tryFire(CompletableFuture.java:852)

at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)

at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:1977)

at org.apache.flink.runtime.concurrent.FutureUtils.lambda$retryOperationWithDelay$8(FutureUtils.java:263)

at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)

at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736)

at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)

at java.util.concurrent.CompletableFuture.postFire(CompletableFuture.java:561)

at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:929)

at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:442)

... 3 more

Caused by: org.apache.flink.runtime.rest.util.RestClientException: [Could not upload job files.]

at org.apache.flink.runtime.rest.RestClient.parseResponse(RestClient.java:389)

at org.apache.flink.runtime.rest.RestClient.lambda$submitRequest$3(RestClient.java:373)

at java.util.concurrent.CompletableFuture.uniCompose(CompletableFuture.java:952)

at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:926)

... 4 more

... (this pattern repeats for number of unique JobIDs)

Caused by: org.apache.flink.runtime.rest.util.RestClientException: [Could not upload job files.]

at org.apache.flink.runtime.rest.RestClient.parseResponse(RestClient.java:389)

at org.apache.flink.runtime.rest.RestClient.lambda$submitRequest$3(RestClient.java:373)

at java.util.concurrent.CompletableFuture.uniCompose(CompletableFuture.java:952)

at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:926)

at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:442)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

at java.lang.Thread.run(Thread.java:745)

...

26 05:46:39,734 [CASHFLOW-18394] WARN  FlinkClusterStateMonitor - Error while attempting to fetch job details for job 4d20537a676df2855e29b31b1de1ead5

com.gs.ep.data.lake.refinerlib.restful.RestfulException: failed connecting to http://d43723-484.dc.gs.com:36757/jobs/4d20537a676df2855e29b31b1de1ead5 after 1 time(s)

Caused by: java.net.ConnectException: Connection refused

at java.net.PlainSocketImpl.socketConnect(Native Method)

at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)

at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)

at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)

at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)

at java.net.Socket.connect(Socket.java:589)

at java.net.Socket.connect(Socket.java:538)

at sun.net.NetworkClient.doConnect(NetworkClient.java:180)

 

These connection refusal exceptions and their transient nature makes me think that it might be a network-related issue. It’s not uncommon for us to need to run 100+ jobs in parallel. How can we investigate what’s causing the Job Manager to periodically refuse connections? I can see a Netty package in the first example’s stack trace – is there any option we can tune?

 

____________

 

Andreas Hailu

Data Lake Engineering | Goldman Sachs & Co.

 




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