incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Alexei Bakanov <russ...@gmail.com>
Subject Secondary index query + 2 Datacenters + Row Cache + Restart = 0 rows
Date Fri, 01 Feb 2013 08:03:39 GMT
Hello,

I've found a combination that doesn't work:
A column family that have a secondary index and caching='ALL' with
data in two datacenters and I do a restart of the nodes, then my
secondary index queries start returning 0 rows.
It happens when amount of data goes over a certain threshold, so I
suspect that compactions are involved in this as well.
Taking out one of the ingredients fixes the problem and my queries
return rows from secondary index.
I suspect that this guy is struggling with the same thing
https://issues.apache.org/jira/browse/CASSANDRA-4785

Here is a sequence of actions that reproduces it with help of CCM:

$ ccm create --cassandra-version 1.2.1 --nodes 2 -p RandomPartitioner
testRowCacheDC
$ ccm updateconf 'endpoint_snitch: PropertyFileSnitch'
$ ccm updateconf 'row_cache_size_in_mb: 200'
$ cp ~/Downloads/cassandra-topology.properties
~/.ccm/testRowCacheDC/node1/conf/      (please find .properties file
below)
$ cp ~/Downloads/cassandra-topology.properties ~/.ccm/testRowCacheDC/node2/conf/
$ ccm start
$ ccm cli
 ->create keyspace and column family(please find schema below)
$ python populate_rowcache.py
$ ccm stop  (I tried flush first, doesn't help)
$ ccm start
$ ccm cli
Connected to: "testRowCacheDC" on 127.0.0.1/9160
Welcome to Cassandra CLI version 1.2.1-SNAPSHOT

Type 'help;' or '?' for help.
Type 'quit;' or 'exit;' to quit.

[default@unknown] use testks;
Authenticated to keyspace: testks
[default@testks] get cf1 where 'indexedColumn'='userId_75';

0 Row Returned.
Elapsed time: 68 msec(s).

My cassandra instances run with -Xms1927M -Xmx1927M -Xmn400M
Thanks for help.

Best regards,
Alexei


------ START cassandra-topology.properties ----------
127.0.0.1=DC1:RAC1
127.0.0.2=DC2:RAC1
default=DC1:r1
------ FINISH cassandra-topology.properties ----------

------ START cassandra-cli schema -----------
create keyspace testks
  with placement_strategy = 'NetworkTopologyStrategy'
  and strategy_options = {DC2 : 1, DC1 : 1}
  and durable_writes = true;

use testks;

create column family cf1
  with column_type = 'Standard'
  and comparator = 'org.apache.cassandra.db.marshal.AsciiType'
  and default_validation_class = 'UTF8Type'
  and key_validation_class = 'UTF8Type'
  and read_repair_chance = 1.0
  and dclocal_read_repair_chance = 0.0
  and gc_grace = 864000
  and min_compaction_threshold = 4
  and max_compaction_threshold = 32
  and replicate_on_write = true
  and compaction_strategy =
'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'
  and caching = 'ALL'
  and column_metadata = [
    {column_name : 'indexedColumn',
    validation_class : UTF8Type,
    index_name : 'INDEX1',
    index_type : 0}]
  and compression_options = {'sstable_compression' :
'org.apache.cassandra.io.compress.SnappyCompressor'};
-------FINISH cassandra-cli schema -----------

------ START populate_rowcache.py -----------
from pycassa.batch import Mutator

import pycassa

pool = pycassa.ConnectionPool('testks', timeout=5)
cf = pycassa.ColumnFamily(pool, 'cf1')

for userId in xrange(0, 1000):
    print userId
    b = Mutator(pool, queue_size=200)
    for itemId in xrange(20):
        rowKey = 'userId_%s:itemId_%s'%(userId, itemId)
        for message_number in xrange(10):
            b.insert(cf, rowKey, {'indexedColumn': 'userId_%s'%userId,
str(message_number): str(message_number)})
    b.send()

pool.dispose()
------ FINISH populate_rowcache.py -----------

Mime
View raw message