[jira] [Commented] (CASSANDRA-6487) Log WARN on large batch sizes

["Martin Grotzke (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-6487?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15013252#comment-15013252 ] 

Martin Grotzke commented on CASSANDRA-6487:
-------------------------------------------

Is the batch size (5kB) also relevant, if
1) a batch writes only a single partition
2) or it contains only a single statement/insert?

Background: We're using [akka-persistence-cassandra|https://github.com/krasserm/akka-persistence-cassandra/] (which writes single events as batch as well AFAICS) and get warnings for ap_messages like {{WARN \[SharedPool-Worker-78] 2015-11-11 17:30:07,489 BatchStatement.java:252 - Batch of prepared statements for \[search.ap_messages] is of size 10243, exceeding specified threshold of 5120 by 5123.}}.
Therefore I'd like to better understand this issue to know better how we should proceed.

> Log WARN on large batch sizes
> -----------------------------
>
>                 Key: CASSANDRA-6487
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-6487
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Patrick McFadin
>            Assignee: Lyuben Todorov
>            Priority: Minor
>             Fix For: 2.0.8, 2.1 beta2
>
>         Attachments: 6487-cassandra-2.0.patch, 6487-cassandra-2.0_v2.patch
>
>
> Large batches on a coordinator can cause a lot of node stress. I propose adding a WARN log entry if batch sizes go beyond a configurable size. This will give more visibility to operators on something that can happen on the developer side. 
> New yaml setting with 5k default.
> {{# Log WARN on any batch size exceeding this value. 5k by default.}}
> {{# Caution should be taken on increasing the size of this threshold as it can lead to node instability.}}
> {{batch_size_warn_threshold: 5k}}



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