[syslog-ng] disk-buffer in elasticsearch2 destination loses messages if docker container is killed
Jose Angel Santiago
jasantiago at stratio.com
Wed Sep 19 13:50:36 UTC 2018
Hi,
You're right, what I saw on my tcpdump file was TCP ACK.
I guess I lose so many messages because the TCP buffer is getting bigger
and bigger since syslog-relay queue_length from disk_buffer reaches its
limit. In fact, when this queue is not full (i.e with very low msg/sec
ratio) I lose from 0-5 messages according to my tests.
Which parameter is the one which would match the queue_length of the
disk_buffer? It seems that it should be *mem-buf-length()* but I'm using
reliable=yes so I shouldn't use that parameter, and I'd like to test my
scenary being able to queue more than 99 messages on disk_buffer.
Thanks.
2018-09-19 13:46 GMT+02:00 Budai, László <laszlo.budai at oneidentity.com>:
> Hi,
>
> what do you mean under 'syslog-relay returns ACK to syslog-ng agent' ?
> I guess this is TCP level ACK.
>
> And TCP level ACK is not the same as what syslog-ng uses for controlling
> the window size of the LogSources.
>
> It is possible that you have pending data in TCP buffers (maintained by
> the kernel) that is not read by syslog-ng, but they are already ACKd by TCP
> itself...
>
> (Solving this kind of situation requires application level ACK, which
> syslog-ng has only in the commercial edition.)
>
> L.
>
>
> On Wed, Sep 19, 2018 at 9:23 AM, Jose Angel Santiago <
> jasantiago at stratio.com> wrote:
>
>> Hi,
>>
>> I've realized that the queue_length of the disk_buffer never goes beyond
>> 99, no matter the ratio message/sec logger process is writing or the value
>> of mem-buf-size or disk-buf-size.
>>
>> Which parameter is the one which would match the queue_length of the
>> disk_buffer? It seems that it should be *mem-buf-length()* but I'm using
>> reliable=yes so I shouldn't use that parameter, and I'd like to test my
>> scenary being able to queue more than 99 messages on disk_buffer.
>>
>> Regards.
>>
>> 2018-09-17 14:33 GMT+02:00 Jose Angel Santiago <jasantiago at stratio.com>:
>>
>>> 3.17.2
>>>
>>> Thanks in advance.
>>>
>>> 2018-09-17 14:31 GMT+02:00 Budai, László <laszlo.budai at oneidentity.com>:
>>>
>>>> Hi,
>>>>
>>>> I'll try to reproduce this issue in my test environment.
>>>> What syslog-ng version do you have?
>>>>
>>>> L.
>>>>
>>>> On Mon, Sep 17, 2018 at 2:04 PM, Jose Angel Santiago <
>>>> jasantiago at stratio.com> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> After repeating the test without TLS between syslog-agent &
>>>>> syslog-relay, with 2229 messages logged with a 20 msgs/sec logging ratio,
>>>>> in debug mode and with two tcpdumps running, these are the conclussions:
>>>>>
>>>>> - Syslog-agent sends every single message (checked with tcpdump file
>>>>> and syslog-agent log file)
>>>>> - Syslog-relay returns ACK for every single message, but sometimes the
>>>>> package contains more than one message (checked with tcpdump file)
>>>>> - Checking the syslog-relay log after killing & starting the docker
>>>>> container, I found the trace 'Reliable disk-buffer state loaded;
>>>>> filename='/syslog-ng-00000.rqf', queue_length='99', size='173844' and
>>>>> the queued messages (from msg 236 to msg 334 are processed). The next
>>>>> message processed is the nº 440. and it comes from the active network
>>>>> destination again.
>>>>> - Once all logs have been processed, in elasticsearch (syslog-relay
>>>>> destination) I can find messages from 1 to 334, and messages from 440 to
>>>>> 2229.
>>>>>
>>>>> How is it possible that syslog-relay returns ACK for messages 335 to
>>>>> 439 to syslog-agent, but they are not in the queue, nor in the .rqf file?
>>>>> Where did these messages go? I know they are sent before starting to fill
>>>>> syslog-agent disk-buffer file (checked with rqf file from syslog-agent when
>>>>> I kill the syslog-relay container). It seems that there's some kind of race
>>>>> condition that makes those messages are not processed/queued while
>>>>> syslog-relay is being killed.
>>>>>
>>>>> Mi procedure consists of:
>>>>>
>>>>> . Start tcpdump on both syslog-agent & syslog-relay hosts
>>>>> - Start logger process
>>>>> - Once logs are being inserted in elasticsearch, I kill the
>>>>> syslog-relay docker container, wait about 10 seconds, and run a new
>>>>> container (using a mapped volume where .rqf file and .persist file are)
>>>>> - Once logs are being inserted in elasticsearch again, I stop the
>>>>> logger process.
>>>>> - I wait until no log is left to be processed
>>>>>
>>>>> Would you test anything else? I'm running out of ideas.
>>>>>
>>>>> PD: Same test with logger process writing 5 msgs/sec ratio produces
>>>>> from 0 to 5 lost messages.
>>>>>
>>>>> Regards.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> 2018-09-14 14:05 GMT+02:00 Jose Angel Santiago <jasantiago at stratio.com
>>>>> >:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I've got more accurate information about where are my lost messages.
>>>>>>
>>>>>> Now I'm using disk-buffer in syslog-agent and syslog-relay, and I've
>>>>>> checked that lost messages are the ones sent by the syslog-agent when the
>>>>>> syslog-relay docker container is being killed. I can see those messages on
>>>>>> syslog-agent log (I've got both agent & relay in debug mode) with its
>>>>>> corresponding "Outgoing message" line, but those messages never reach the
>>>>>> relay.
>>>>>>
>>>>>> Could it be that the relay docker container still returns ACK to the
>>>>>> agent (the agent resolves relay fqdn with a custom DNS) while syslog-ng
>>>>>> process within the container is being stopped? I'm about to test again
>>>>>> using tcpdump to confirm this theory,
>>>>>>
>>>>>> BTW, disk-buffers works ok, sometimes I get some duplicated messages
>>>>>> when restarting the relay but that's not a problem for me. Forget about my
>>>>>> .persist file re-creation theory, it doesn't happen.
>>>>>>
>>>>>> Regards.
>>>>>>
>>>>>>
>>>>>>
>>>>>> 2018-09-13 18:07 GMT+02:00 Péter, Kókai <peter.kokai at oneidentity.com>
>>>>>> :
>>>>>>
>>>>>>> Hello,
>>>>>>>
>>>>>>> It would not make sense to replace the persist file after restart,
>>>>>>> so it is not something that syslog-ng does. Only if that file is corrupted,
>>>>>>> in that case at startup there should be a log about it, have you checked
>>>>>>> the syslog-ng logs ? (it would be better to enable debug and/or verbose
>>>>>>> logs, and if possible share it with us.)
>>>>>>>
>>>>>>> Could you reproduce the same behavior without docker (if possible) ?
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Best Regards,
>>>>>>> Peter Kokai
>>>>>>>
>>>>>>> On Thu, Sep 13, 2018 at 4:44 PM Jose Angel Santiago <
>>>>>>> jasantiago at stratio.com> wrote:
>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> I guess I know what is happening, when I start from scratch the
>>>>>>>> docker container, even I provide a persist file and a buffer file within
>>>>>>>> the mapped volume, syslog-ng recreates them so all messages in buffer file
>>>>>>>> which were not processed by the relay are lost.
>>>>>>>>
>>>>>>>> Is there any way to tell syslog-ng to use an already existing
>>>>>>>> .persist file so it doesn't recreate the .rqf file?
>>>>>>>>
>>>>>>>> Regards.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> 2018-09-13 16:23 GMT+02:00 Budai, László <
>>>>>>>> laszlo.budai at oneidentity.com>:
>>>>>>>>
>>>>>>>>> Hi,
>>>>>>>>>
>>>>>>>>> one problem could be if the flush-limit would be greater than 1...
>>>>>>>>> in that case syslog-ng would use a HttpBulkMessageProcessor.
>>>>>>>>> In this case syslog-ng pass the message to the
>>>>>>>>> HttpBulkMessageProcessor and sends back a positive ACK to the LogSource (so
>>>>>>>>> the message is removed from the diskbuffer), and if the dockerimage is
>>>>>>>>> killed, all the messages stored in the HttpBulkMessageProcessor are lost.
>>>>>>>>> But in your case syslog-ng should use the
>>>>>>>>> HttpSingleMessageProcessor... which means that the messages are sent
>>>>>>>>> one-by-one...
>>>>>>>>> Could you check the diskbuffer with the dqtool?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> L.
>>>>>>>>>
>>>>>>>>> On Thu, Sep 13, 2018 at 3:50 PM, Jose Angel Santiago <
>>>>>>>>> jasantiago at stratio.com> wrote:
>>>>>>>>>
>>>>>>>>>> Hi,
>>>>>>>>>>
>>>>>>>>>> I'm running syslog-ng (with an elasticsearch2 destination
>>>>>>>>>> configured) within a docker container, and I'm trying to avoid loss of
>>>>>>>>>> messages if I kill the docker container and I start it again.
>>>>>>>>>>
>>>>>>>>>> This is my scenary:
>>>>>>>>>>
>>>>>>>>>> - A service which produces 20 lines of log per second
>>>>>>>>>> - A sislog-ng instance reading from a wildcard-file source (but
>>>>>>>>>> actually it only reads logs from the above service, let's call it
>>>>>>>>>> syslog-agent), which sends all logs to another syslog-ng instance (the one
>>>>>>>>>> running in a docker container, let's call it syslog-relay) though a network
>>>>>>>>>> destination.
>>>>>>>>>> - The syslog-relay sends messages to an elasticsearch instance,
>>>>>>>>>> with following configuration:
>>>>>>>>>>
>>>>>>>>>> options {
>>>>>>>>>> chain-hostnames(no);
>>>>>>>>>> use-dns(no);
>>>>>>>>>> keep-hostname(yes);
>>>>>>>>>> owner("syslog-ng");
>>>>>>>>>> group("stratio");
>>>>>>>>>> perm(0640);
>>>>>>>>>> time-reap(30);
>>>>>>>>>> mark-freq(10);
>>>>>>>>>> stats-freq(0);
>>>>>>>>>> bad-hostname("^gconfd$");
>>>>>>>>>> flush-lines(100);
>>>>>>>>>> log-fifo-size(1000);
>>>>>>>>>> };
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> *destination d_elastic_default_0 { elasticsearch2(
>>>>>>>>>> cluster("myelastic") cluster-url("https://myelastic.logs:9200
>>>>>>>>>> <https://myelastic.logs:9200>") client_mode("https")
>>>>>>>>>> index("default") type("log") flush-limit(1)
>>>>>>>>>> disk-buffer( mem-buf-size(16M)
>>>>>>>>>> disk-buf-size(16M) reliable(yes)
>>>>>>>>>> dir("/syslog-ng/log") ) http-auth-type("clientcert")
>>>>>>>>>> java-keystore-filepath("/etc/syslog-ng/certificates/syslog-relay.jks")
>>>>>>>>>> java-keystore-password("XXXXXX")
>>>>>>>>>> java-truststore-filepath("/etc/syslog-ng/certificates/ca-bundle.jks")
>>>>>>>>>> java-truststore-password("XXXXXXXXXX") );};*
>>>>>>>>>>
>>>>>>>>>> - The dir "/syslog-ng/log" is mapped to a path "/tmp/buffer" from
>>>>>>>>>> the host where the docker container is running, so when I kill the docker
>>>>>>>>>> container, the buffer file is not lost.
>>>>>>>>>> - I've set flush-limit to 1 because I thought that I may lost 1
>>>>>>>>>> message only as much.
>>>>>>>>>>
>>>>>>>>>> This architecture is working fine (flush-limit=1 makes very slow,
>>>>>>>>>> but for this test is ok), but if I kill the syslog-relay docker container,
>>>>>>>>>> wait 5 to 10 seconds and start it again from scratch, I can see that
>>>>>>>>>> several hundreds of logs are missing in elasticsearch. I check it by
>>>>>>>>>> stopping the logger service and letting syslog-ng agent & relay to finish
>>>>>>>>>> the process enqueued messages.
>>>>>>>>>>
>>>>>>>>>> I can see in the syslog-agent stats that all logs messages have
>>>>>>>>>> been processed, so it seems the problem is on the syslog-relay.
>>>>>>>>>>
>>>>>>>>>> Is this behaviour expected? If so, how can I protect against loss
>>>>>>>>>> of messages in case of a syslog-relay docker container unexpected kill?
>>>>>>>>>>
>>>>>>>>>> Thanks in advance.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>>
>>>>>>>>>> | Jose Angel Santiago
>>>>>>>>>>
>>>>>>>>>> [image: Logo_signature2.png] <http://www.stratio.com/>
>>>>>>>>>>
>>>>>>>>>> Vía de las dos Castillas, 33, Ática 4, 3ª Planta
>>>>>>>>>>
>>>>>>>>>> 28224 Pozuelo de Alarcón, Madrid, Spain
>>>>>>>>>>
>>>>>>>>>> +34 918 286 473 <+34%20918%2028%2064%2073> | www.stratio.com
>>>>>>>>>> <https://twitter.com/stratiobd>
>>>>>>>>>> <https://www.linkedin.com/company/stratiobd>
>>>>>>>>>> <https://www.youtube.com/c/StratioBD>
>>>>>>>>>>
>>>>>>>>>> ____________________________________________________________
>>>>>>>>>> __________________
>>>>>>>>>> Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng
>>>>>>>>>> Documentation: http://www.balabit.com/support
>>>>>>>>>> /documentation/?product=syslog-ng
>>>>>>>>>> FAQ: http://www.balabit.com/wiki/syslog-ng-faq
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> ____________________________________________________________
>>>>>>>>> __________________
>>>>>>>>> Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng
>>>>>>>>> Documentation: http://www.balabit.com/support
>>>>>>>>> /documentation/?product=syslog-ng
>>>>>>>>> FAQ: http://www.balabit.com/wiki/syslog-ng-faq
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>>
>>>>>>>> | Jose Angel Santiago
>>>>>>>>
>>>>>>>> [image: Logo_signature2.png] <http://www.stratio.com/>
>>>>>>>>
>>>>>>>> Vía de las dos Castillas, 33, Ática 4, 3ª Planta
>>>>>>>>
>>>>>>>> 28224 Pozuelo de Alarcón, Madrid, Spain
>>>>>>>>
>>>>>>>> +34 918 286 473 <+34%20918%2028%2064%2073> | www.stratio.com
>>>>>>>> <https://twitter.com/stratiobd>
>>>>>>>> <https://www.linkedin.com/company/stratiobd>
>>>>>>>> <https://www.youtube.com/c/StratioBD>
>>>>>>>> ____________________________________________________________
>>>>>>>> __________________
>>>>>>>> Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng
>>>>>>>> Documentation: http://www.balabit.com/support
>>>>>>>> /documentation/?product=syslog-ng
>>>>>>>> FAQ: http://www.balabit.com/wiki/syslog-ng-faq
>>>>>>>>
>>>>>>>>
>>>>>>> ____________________________________________________________
>>>>>>> __________________
>>>>>>> Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng
>>>>>>> Documentation: http://www.balabit.com/support
>>>>>>> /documentation/?product=syslog-ng
>>>>>>> FAQ: http://www.balabit.com/wiki/syslog-ng-faq
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>>
>>>>>> | Jose Angel Santiago
>>>>>>
>>>>>> [image: Logo_signature2.png] <http://www.stratio.com/>
>>>>>>
>>>>>> Vía de las dos Castillas, 33, Ática 4, 3ª Planta
>>>>>>
>>>>>> 28224 Pozuelo de Alarcón, Madrid, Spain
>>>>>>
>>>>>> +34 918 286 473 | www.stratio.com
>>>>>> <https://twitter.com/stratiobd>
>>>>>> <https://www.linkedin.com/company/stratiobd>
>>>>>> <https://www.youtube.com/c/StratioBD>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>>
>>>>> | Jose Angel Santiago
>>>>>
>>>>> [image: Logo_signature2.png] <http://www.stratio.com/>
>>>>>
>>>>> Vía de las dos Castillas, 33, Ática 4, 3ª Planta
>>>>>
>>>>> 28224 Pozuelo de Alarcón, Madrid, Spain
>>>>>
>>>>> +34 918 286 473 | www.stratio.com
>>>>> <https://twitter.com/stratiobd>
>>>>> <https://www.linkedin.com/company/stratiobd>
>>>>> <https://www.youtube.com/c/StratioBD>
>>>>>
>>>>> ____________________________________________________________
>>>>> __________________
>>>>> Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng
>>>>> Documentation: http://www.balabit.com/support
>>>>> /documentation/?product=syslog-ng
>>>>> FAQ: http://www.balabit.com/wiki/syslog-ng-faq
>>>>>
>>>>>
>>>>>
>>>>
>>>> ____________________________________________________________
>>>> __________________
>>>> Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng
>>>> Documentation: http://www.balabit.com/support
>>>> /documentation/?product=syslog-ng
>>>> FAQ: http://www.balabit.com/wiki/syslog-ng-faq
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>>
>>> | Jose Angel Santiago
>>>
>>> [image: Logo_signature2.png] <http://www.stratio.com/>
>>>
>>> Vía de las dos Castillas, 33, Ática 4, 3ª Planta
>>>
>>> 28224 Pozuelo de Alarcón, Madrid, Spain
>>>
>>> +34 918 286 473 | www.stratio.com
>>> <https://twitter.com/stratiobd>
>>> <https://www.linkedin.com/company/stratiobd>
>>> <https://www.youtube.com/c/StratioBD>
>>>
>>
>>
>>
>> --
>>
>> | Jose Angel Santiago
>>
>> [image: Logo_signature2.png] <http://www.stratio.com/>
>>
>> Vía de las dos Castillas, 33, Ática 4, 3ª Planta
>>
>> 28224 Pozuelo de Alarcón, Madrid, Spain
>>
>> +34 918 286 473 | www.stratio.com
>> <https://twitter.com/stratiobd>
>> <https://www.linkedin.com/company/stratiobd>
>> <https://www.youtube.com/c/StratioBD>
>>
>> ____________________________________________________________
>> __________________
>> Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng
>> Documentation: http://www.balabit.com/support
>> /documentation/?product=syslog-ng
>> FAQ: http://www.balabit.com/wiki/syslog-ng-faq
>>
>>
>>
>
> ____________________________________________________________
> __________________
> Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng
> Documentation: http://www.balabit.com/support/documentation/?
> product=syslog-ng
> FAQ: http://www.balabit.com/wiki/syslog-ng-faq
>
>
>
--
| Jose Angel Santiago
[image: Logo_signature2.png] <http://www.stratio.com/>
Vía de las dos Castillas, 33, Ática 4, 3ª Planta
28224 Pozuelo de Alarcón, Madrid, Spain
+34 918 286 473 | www.stratio.com
<https://twitter.com/stratiobd> <https://www.linkedin.com/company/stratiobd>
<https://www.youtube.com/c/StratioBD>
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