# Graylog Output Working but with Errors **URL:** \ **Category:** Graylog Central (peer support)\ **Created:** [September 11, 2017, 7:17am UTC](https://community.graylog.org/t/graylog-output-working-but-with-errors/2398 "2017-09-11T07:17:08Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![janc](https://avatars.discourse-cdn.com/v4/letter/j/7bcc69/32.png) [@janc](https://community.graylog.org/u/janc)\ **Post date:** [September 11, 2017, 7:17am UTC](https://community.graylog.org/t/graylog-output-working-but-with-errors/2398/1 "2017-09-11T07:17:08Z")
Hello, Currently I have two Graylog Deployments. One that receives a lot of messages from various sources (let’s call it BIG) and another one mainly for receiving logs from first graylog site (let’s call it SMALL). I am trying to output a stream from BIG to SMALL and it seem to be working through GelfOutput and GelfInput TCP. However I’ve been receiving a lot of errors like the following: ```auto 2017-09-11T07:01:54.428Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String at org.graylog2.outputs.GelfOutput.toGELFMessage(GelfOutput.java:245) ~[graylog.jar:?] at org.graylog2.outputs.GelfOutput.write(GelfOutput.java:184) ~[graylog.jar:?] at org.graylog2.buffers.processors.OutputBufferProcessor$1.run(OutputBufferProcessor.java:194) [graylog.jar:?] at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:176) [graylog.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_121] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_121] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121] ``` AND a lot of ```auto ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null ``` I’ve tried using UDP output and INPUT however results are still the same: Currently I’m running with TCP and still keep on receiving errors. Has anyone encountered this before? Also, when TCP output is running, sometimes indexing will suddenly stop working, with the outputbuffer empty and processbuffer full. I would have to restart BIG graylog-servers in order to get it back to normal. Thanks ---
**Author:** ![jochen](https://sea2.discourse-cdn.com/flex016/user_avatar/community.graylog.org/jochen/32/8_2.png) [@jochen](https://community.graylog.org/u/jochen)\ **Post date:** [September 11, 2017, 7:51am UTC](https://community.graylog.org/t/graylog-output-working-but-with-errors/2398/2 "2017-09-11T07:51:28Z")
> [@janc](#): > > ```auto > 2017-09-11T07:01:54.428Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String > at org.graylog2.outputs.GelfOutput.toGELFMessage(GelfOutput.java:245) ~[graylog.jar:?] > > ``` Graylog (or more specifically the GELF output) expects the “facility” message field to be a string, but it was a number (of type `Long`) in this case. This is a bug and should be fixed. Please create a bug report with the complete error message (and possibly a link to this topic) at [Issues · Graylog2/graylog2-server · GitHub](https://github.com/Graylog2/graylog2-server/issues) > [@janc](#): > > ```auto > ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null > > ``` Please post the following line(s) of this error message. Otherwise we cannot identify the root of the problem. ---
**Author:** ![janc](https://avatars.discourse-cdn.com/v4/letter/j/7bcc69/32.png) [@janc](https://community.graylog.org/u/janc)\ **Post date:** [September 12, 2017, 2:49am UTC](https://community.graylog.org/t/graylog-output-working-but-with-errors/2398/3 "2017-09-12T02:49:52Z")
Thanks for the response. Although, would you recommend any workaround to output logs to another graylog through gelf without having to force facility to string? I have tried using another syslog output plugin, which is not showing any errors but still no messages are being received on the other end. As for the second error, I believe both the first one and this are related. Here’s an excerpt from the logfile: ```auto 2017-09-12T02:05:18.622Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String at org.graylog2.outputs.GelfOutput.toGELFMessage(GelfOutput.java:245) ~[graylog.jar:?] at org.graylog2.outputs.GelfOutput.write(GelfOutput.java:184) ~[graylog.jar:?] at org.graylog2.buffers.processors.OutputBufferProcessor$1.run(OutputBufferProcessor.java:194) [graylog.jar:?] at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:176) [graylog.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_121] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_121] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121] 2017-09-12T02:05:18.934Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String at org.graylog2.outputs.GelfOutput.toGELFMessage(GelfOutput.java:245) ~[graylog.jar:?] at org.graylog2.outputs.GelfOutput.write(GelfOutput.java:184) ~[graylog.jar:?] at org.graylog2.buffers.processors.OutputBufferProcessor$1.run(OutputBufferProcessor.java:194) [graylog.jar:?] at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:176) [graylog.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_121] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_121] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121] 2017-09-12T02:05:18.934Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String at org.graylog2.outputs.GelfOutput.toGELFMessage(GelfOutput.java:245) ~[graylog.jar:?] at org.graylog2.outputs.GelfOutput.write(GelfOutput.java:184) ~[graylog.jar:?] at org.graylog2.buffers.processors.OutputBufferProcessor$1.run(OutputBufferProcessor.java:194) [graylog.jar:?] at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:176) [graylog.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_121] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_121] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121] 2017-09-12T02:05:19.034Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String at org.graylog2.outputs.GelfOutput.toGELFMessage(GelfOutput.java:245) ~[graylog.jar:?] at org.graylog2.outputs.GelfOutput.write(GelfOutput.java:184) ~[graylog.jar:?] at org.graylog2.buffers.processors.OutputBufferProcessor$1.run(OutputBufferProcessor.java:194) [graylog.jar:?] at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:176) [graylog.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_121] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_121] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_121] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121] 2017-09-12T02:05:23.572Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:24.733Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:24.955Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:26.689Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:26.934Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:27.351Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:28.377Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:28.462Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:29.367Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:29.708Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:29.803Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:29.879Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:30.562Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:31.880Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:32.666Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. java.lang.ClassCastException: null 2017-09-12T02:05:34.863Z ERROR [OutputBufferProcessor] Error in output [class org.graylog2.outputs.GelfOutput]. ``` Thanks ---
**Author:** ![jochen](https://sea2.discourse-cdn.com/flex016/user_avatar/community.graylog.org/jochen/32/8_2.png) [@jochen](https://community.graylog.org/u/jochen)\ **Post date:** [September 12, 2017, 3:10pm UTC](https://community.graylog.org/t/graylog-output-working-but-with-errors/2398/4 "2017-09-12T15:10:52Z")
Follow up: > > > Expected Behavior > The GELF output successfully sends the message even if "facility" is not a string > Current Behavior > The GELF output fails with the... ---
**Author:** ![janc](https://avatars.discourse-cdn.com/v4/letter/j/7bcc69/32.png) [@janc](https://community.graylog.org/u/janc)\ **Post date:** [September 14, 2017, 2:04am UTC](https://community.graylog.org/t/graylog-output-working-but-with-errors/2398/5 "2017-09-14T02:04:43Z")
Thanks for filing the bug report. As a workaround, we used pipelines to ensure facility fields are strings, the logs are now being forwarded. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/graylog/original/3X/c/7/c7c09c6b5099570133d6502b83f50ba4430de5b6.png) [@system](https://community.graylog.org/u/system)\ **Post date:** [September 28, 2017, 2:05am UTC](https://community.graylog.org/t/graylog-output-working-but-with-errors/2398/6 "2017-09-28T02:05:06Z")
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