Worker - lost connecton

Camunda 7 Topics Discussion & Questions
1

Hi Dear Camunders,

lately I have experienced kind of anomaly which I think was caused when worker (1.3) lost connection to the Camunda engine (7.12.2) and couldn’t continue working.

Any advice for such cases? I don’t want to amend any Camunda code. So far my idea is to use cron and kill/start workers every x hours.

Thank you for any advice

The External Task a4900d51-cccc-11ea-a4a7-0242ac170007 has been completed! with workerId: VECWorker
3082990768 [TopicSubscriptionManager] ERROR org.camunda.bpm.client - TASK/CLIENT-03001 Exception while fetch and lock task.
org.camunda.bpm.client.impl.EngineClientException: TASK/CLIENT-02002 Exception while establishing connection for request 'POST http://1.1111.00.11:1234/engine-rest/external-task/fetchAndLock HTTP/1.1'
        at org.camunda.bpm.client.impl.EngineClientLogger.exceptionWhileEstablishingConnection(EngineClientLogger.java:36)
        at org.camunda.bpm.client.impl.RequestExecutor.executeRequest(RequestExecutor.java:101)
        at org.camunda.bpm.client.impl.RequestExecutor.postRequest(RequestExecutor.java:74)
        at org.camunda.bpm.client.impl.EngineClient.fetchAndLock(EngineClient.java:78)
        at org.camunda.bpm.client.topic.impl.TopicSubscriptionManager.fetchAndLock(TopicSubscriptionManager.java:135)
        at org.camunda.bpm.client.topic.impl.TopicSubscriptionManager.acquire(TopicSubscriptionManager.java:101)
        at org.camunda.bpm.client.topic.impl.TopicSubscriptionManager.run(TopicSubscriptionManager.java:87)
        at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.http.NoHttpResponseException: 1.1111.00.11:1234 failed to respond
        at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:141)
        at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:56)
        at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:259)
        at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:163)
        at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:157)
        at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:273)
        at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:125)
        at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:272)
        at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186)
        at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89)
        at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
        at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:72)
        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:221)
        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:165)
        at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:140)
        at org.camunda.bpm.client.impl.RequestExecutor.executeRequest(RequestExecutor.java:88)
2

Have a look at this similar bug report, you may want to tweak your backoff strategy. What OS and JDK versions are you using?

3

Hi @jgigliotti,

The worker is on RedHat machine using JDK 1.8 .
Thank you for the bug link will try to play a bit around.

M.

4