[jira] Commented: (CASSANDRA-1093) BinaryMemtable interface silently dropping data.

["Jonathan Ellis (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-1093?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12887832#action_12887832 ] 

Jonathan Ellis commented on CASSANDRA-1093:
-------------------------------------------

BMT is a very fire-and-forget api, so any failure condition will cause messages to be dropped with no way of knowing.

Probably the most likely one is, under heavy load (network and/or cpu) it's reasonably common for one node in the cluster to be marked "down" incorrectly by other nodes in the cluster.  This causes any messages on the MessagingService queue to that node to be dropped summarily, and the pool connection to be re-attempted when the failure detector believes it is "up" again.  (See OutboundTcpConnectionPool.reset)

> BinaryMemtable interface silently dropping data.
> ------------------------------------------------
>
>                 Key: CASSANDRA-1093
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-1093
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>         Environment: Linux Centos5, Fedora Core 4. Java HotSpot Server 1.6.0_14. See readme for more details.
>            Reporter: Toby Jungen
>            Assignee: Brandon Williams
>             Fix For: 0.6.3
>
>         Attachments: cassandra_bmt_test.tar.gz
>
>
> I've been attempting to use the Binary Memtable (BMT) interface to load a large number of rows. During my testing, I discovered that on larger loads (~1 million rows), occasionally some of the data never appears in the database. This happens in a non-deterministic manner, as sometimes all the data loads fine, and other times a significant chunk goes missing. No errors are ever logged to indicate a problem. I'm attaching some sample code that approximates my application's usage of Cassandra and explains this bug in more detail.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.