[jira] [Commented] (KAFKA-2338) Warn users if they change max.message.bytes that they also need to update broker and consumer settings

[Edward Ribeiro (JIRA)]

    [ 
https://issues.apache.org/jira/browse/KAFKA-2338?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14709707#comment-14709707
 ] 

Edward Ribeiro commented on KAFKA-2338:
---------------------------------------

Hi, [~gwenshap], thanks for the kind words. :) I am sorry for not being able to 
give the necessary love to this patch :( (much because of my inexperience with 
the code base, I guess). I hope I can dig more about max message size problems 
soon tough. I have just rebased the patch and it compiles successfully now with 
latest trunk.

Oh, one thing that has caught my attention is that some chunk of code (below) 
was removed from TopicCommand, specifically in the alterTopic() method, in the 
context of KAFKA-2198 (a7e0ac):. Seems to indicate that now topic configuration 
cannot be altered, right?

{code}
      val configs = AdminUtils.fetchTopicConfig(zkClient, topic)
      if(opts.options.has(opts.configOpt) || 
opts.options.has(opts.deleteConfigOpt)) {
        val configsToBeAdded = parseTopicConfigsToBeAdded(opts)
        val configsToBeDeleted = parseTopicConfigsToBeDeleted(opts)
        // compile the final set of configs
        configs.putAll(configsToBeAdded)
        configsToBeDeleted.foreach(config => configs.remove(config))
        AdminUtils.changeTopicConfig(zkClient, topic, configs)
        println("Updated config for topic \"%s\".".format(topic))
      }
{code}

Sorry if my doubt is naive/stupid. And feel free to merge this patch, but take 
a look to see if I am doing it right. :) 

Thanks!
Edward

> Warn users if they change max.message.bytes that they also need to update 
> broker and consumer settings
> ------------------------------------------------------------------------------------------------------
>
>                 Key: KAFKA-2338
>                 URL: https://issues.apache.org/jira/browse/KAFKA-2338
>             Project: Kafka
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 0.8.2.1
>            Reporter: Ewen Cheslack-Postava
>            Assignee: Edward Ribeiro
>             Fix For: 0.8.3
>
>         Attachments: KAFKA-2338.patch, KAFKA-2338_2015-07-18_00:37:31.patch, 
> KAFKA-2338_2015-07-21_13:21:19.patch, KAFKA-2338_2015-08-24_14:32:38.patch
>
>
> We already have KAFKA-1756 filed to more completely address this issue, but 
> it is waiting for some other major changes to configs to completely protect 
> users from this problem.
> This JIRA should address the low hanging fruit to at least warn users of the 
> potential problems. Currently the only warning is in our documentation.
> 1. Generate a warning in the kafka-topics.sh tool when they change this 
> setting on a topic to be larger than the default. This needs to be very 
> obvious in the output.
> 2. Currently, the broker's replica fetcher isn't logging any useful error 
> messages when replication can't succeed because a message size is too large. 
> Logging an error here would allow users that get into a bad state to find out 
> why it is happening more easily. (Consumers should already be logging a 
> useful error message.)



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)