Jonathan,
good to know this is normal. but the reason i sent this is , once i stop and start cassandra it gets ready in few seconds and insertion and get_slices are super fast like few milliseconds.

but after it starts to slow down even after 10 hours it is still slow. why is this the case?

On Mon, Jul 13, 2009 at 6:14 AM, Jonathan Ellis <jbellis@gmail.com> wrote:
Cassandra is replaying the transaction log and preloading SSTable
indexes.  This is normal.

On Mon, Jul 13, 2009 at 8:10 AM, rkmr.em@gmail.com<rkmr.em@gmail.com> wrote:
> when i stop cassandra and start it again, this is what is printed. it takes
> just a couple of seconds for this to run.
> and after that it becomes really fast.
>
>
> Listening for transport dt_socket at address: 8888
> DEBUG - Loading settings from ./../conf/storage-conf.xml
> DEBUG - adding Super1 as 0
> DEBUG - adding Standard2 as 1
> DEBUG - adding Standard1 as 2
> DEBUG - adding StandardByTime1 as 3
> DEBUG - adding LocationInfo as 4
> DEBUG - adding HintsColumnFamily as 5
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Super1-9-Data.db: 400 ms.
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Super1-52-Data.db: 300 ms.
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Super1-92-Data.db: 300 ms.
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Super1-138-Data.db: 751 ms.
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Super1-150-Data.db: 100 ms.
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Super1-152-Data.db: 50 ms.
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Super1-154-Data.db: 100 ms.
> INFO - Compacting
> [/home/mark/local/var/cassandra/data/Table1-Super1-138-Data.db,/home/mark/local/var/cassandra/data/Table1-Super1-150-Data.db,/home/mark/local/var/cassandra/data/Table1-Super1-152-Data.db,/home/mark/local/var/cassandra/data/Table1-Super1-154-Data.db]
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Standard1-2-Data.db: 0 ms.
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Standard1-4-Data.db: 50 ms.
> DEBUG - INDEX LOAD TIME for
> /home/mark/local/var/cassandra/data/Table1-Standard1-6-Data.db: 0 ms.
> INFO - Replaying
> /home/mark/local/var/cassandra/commitlog/CommitLog-1247454203796.log
> DEBUG - index size for bloom filter calc for file  :
> /home/mark/local/var/cassandra/data/Table1-Super1-138-Data.db   : 73600
> DEBUG - index size for bloom filter calc for file  :
> /home/mark/local/var/cassandra/data/Table1-Super1-150-Data.db   : 84224
> DEBUG - index size for bloom filter calc for file  :
> /home/mark/local/var/cassandra/data/Table1-Super1-152-Data.db   : 94848
> DEBUG - index size for bloom filter calc for file  :
> /home/mark/local/var/cassandra/data/Table1-Super1-154-Data.db   : 105472
> DEBUG - Expected bloom filter size : 105472
> INFO - Compacted to
> /home/mark/local/var/cassandra/data/Table1-Super1-139-Data.db.  0/28831084
> bytes for 104856/104860 keys read/written.  Time: 8119ms.
> INFO - Flushing Memtable(Super1)@552364977
> DEBUG - Submitting Super1 for compaction
> INFO - Completed flushing Memtable(Super1)@552364977
> INFO - Flushing Memtable(Standard1)@1290243769
> DEBUG - Submitting Standard1 for compaction
> INFO - Completed flushing Memtable(Standard1)@1290243769
> INFO - Compacting
> [/home/mark/local/var/cassandra/data/Table1-Standard1-2-Data.db,/home/mark/local/var/cassandra/data/Table1-Standard1-4-Data.db,/home/mark/local/var/cassandra/data/Table1-Standard1-6-Data.db,/home/mark/local/var/cassandra/data/Table1-Standard1-8-Data.db]
> DEBUG - index size for bloom filter calc for file  :
> /home/mark/local/var/cassandra/data/Table1-Standard1-2-Data.db   : 256
> DEBUG - index size for bloom filter calc for file  :
> /home/mark/local/var/cassandra/data/Table1-Standard1-4-Data.db   : 512
> DEBUG - index size for bloom filter calc for file  :
> /home/mark/local/var/cassandra/data/Table1-Standard1-6-Data.db   : 768
> DEBUG - index size for bloom filter calc for file  :
> /home/mark/local/var/cassandra/data/Table1-Standard1-8-Data.db   : 1024
> DEBUG - Expected bloom filter size : 1024
> INFO - Compacted to
> /home/mark/local/var/cassandra/data/Table1-Standard1-3-Data.db.  0/210 bytes
> for 0/1 keys read/written.  Time: 301ms.
> DEBUG - Starting to listen on 127.0.0.1:7001
> INFO - Cassandra starting up...
>
>
>
> On Mon, Jul 13, 2009 at 6:06 AM, rkmr.em@gmail.com <rkmr.em@gmail.com>
> wrote:
>>
>> how do i find out if JVM is GCing?
>>
>> On Sun, Jul 12, 2009 at 10:37 PM, Sandeep Tata <sandeep.tata@gmail.com>
>> wrote:
>>>
>>> What hardware are you running one?
>>
>>  dual quadcore intel xeon 2.0 ghz, 32GB ram, and hardware raid config
>> operating system is fedora core 9
>>
>>
>>> How long does the slowdown last ?
>>
>> i stopped inserting data after slowdown starts, and it is still slow now
>> after over 10 hours.
>> however if i stop cassandra and start it, it becomes super fast
>> immediately. till i insert another 100k or so rows when it becomes really
>> slow again.
>>
>>
>>>
>>>  There are a few reasons for temporary slowdowns ... perhaps the JVM
>>> started GCing?
>>
>> how do i find out if this is the cause?
>>
>>
>>>
>>> Cassandra spends time cleaning up the on-disk SSTables
>>> in a process called compaction. This could cause the client to observe
>>> a slowdown.
>>>
>>> Things you could try --
>>> Reduce the Memtable size in the config files. (If GCing was the problem)
>>> Increasing the number of SSTables written before compaction kicks in.
>>
>> can you tell me what numbers i should use?
>>
>> thanks!
>>
>
>