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From aaron morton <>
Subject Re: Long Startup Times
Date Mon, 16 Apr 2012 20:24:58 GMT
If you start with DEBUG logging (or just enable logging for SSTableReader) you will get some
more information on what's taking time at startup. 

If you want to dig a little further take a look at the iostat and cpu load. During startup
a thread is created for each core on the machine and used to open a file. I've wondered if
this could overload the IO on machines that report 16 cores.

You'll see messages like this INFO [SSTableBatchOpen:1] where the number is the thread number.


Aaron Morton
Freelance Developer

On 16/04/2012, at 5:13 AM, Derek Barnes wrote:

> Hi,
> I have 2 column families with approx 50 GB of compressed data (~150GB uncompressed).
 The data resides in a keyspace replicated 2-way, hosted by a 2-node Cassandra cluster (v1.0.8),
both with 74GB RAM and 16 cores.    Key caches are set to 1.0. 
> I'm noticing that it can take upwards of 15+ minutes for the node to start up (i.e. before
it becomes responsive to thrift clients).  During this time, the logs suggest the system is
blocked opening the data files. 
> Is this expected behaviour?  Are there any best practices for reducing node startup time?

> Thanks in advance!

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