[syslog-ng] disk-buffer in elasticsearch2 destination loses messages if docker container is killed

Jose Angel Santiago jasantiago at stratio.com
Wed Sep 19 07:23:31 UTC 2018


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>
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