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https://issues.apache.org/jira/browse/CASSANDRA-981?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12914374#action_12914374
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Wouter de Bie commented on CASSANDRA-981:
-----------------------------------------
There seems to be a bug in the 0.6.5 DatabaseDescriptor.java. On line 629:
{noformat}
String dynamic = System.getProperty("cassandra.dynamic_snitch");
if (dynamic == null || Boolean.getBoolean(dynamic) == false)
epSnitch = snitch;
else
epSnitch = new DynamicEndpointSnitch(snitch);
{noformat}
Boolean.getBoolean(String s) checks for System.getProperty(). I think the code
should read:
{noformat}
if (Boolean.getBoolean('cassandra.dynamic_snitch') == false)
epSnitch = snitch;
else
epSnitch = new DynamicEndpointSnitch(snitch);
{noformat}
A workaround is to supply JVM properties like
"-Dcassandra.dynamic_snitch_enabled=true
-Dcassandra.dynamic_snitch=cassandra.dynamic_snitch_enabled"
Has anyone succesfully run with 0.6.5 and the dynamic snitch?
> Dynamic endpoint snitch
> -----------------------
>
> Key: CASSANDRA-981
> URL: https://issues.apache.org/jira/browse/CASSANDRA-981
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Reporter: Jonathan Ellis
> Assignee: Brandon Williams
> Fix For: 0.6.5
>
> Attachments: 981-0.6.txt, 981-fix-v2.txt, 981-fix.txt, 981.txt
>
>
> An endpoint snitch that automatically and dynamically infers "distance" to
> other machines without having to explicitly configure rack and datacenter
> positions solves two problems:
> The killer feature here is adapting to things like compaction or a
> failing-but-not-yet-dead disk. This is important, since when we are doing
> reads we pick the "closest" replica for actually reading data from (and only
> read md5s from other replicas). This means that if the closest replica by
> network topology is temporarily slow due to compaction (for instance), we'll
> have to block for its reply even if we get the other replies much much faster.
> Not having to manually re-sync your configuration with your network topology
> when changes (adding machines) are made is a nice bonus.
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