more info:
CL = ONE,
replica = 2,
and when I tried to monitor the disk_io with iostat I get almost 0MB/s
read & 0% CPU on the machine the scan-data app started on.
Thanks!
-------- ???????? --------
??????: Shuai Yuan <yuansh...@supertool.net.cn>
??????: user@cassandra.apache.org
????: [***SPAM*** ] problem when trying to get_range_slice()
????: Thu, 03 Jun 2010 15:57:14 +0800
Hi all,
----my env----
6 servers with about 200GB data.
data structure,
64B rowkey + (5B column)*20,
rowkey and column.value are all random bytes from a-z,A-Z,0-9
----problem----
when I tried iterate over the data in the storage, I always get
org::apache::cassandra::TimedOutException
(RpcTimeout = 2minutes)
----questions----
1.How could I iterate over my data then?
2.In the code below, I gave key_start/end/count twice, one for
get_range_slice() and the other for SlicePreditor. Are they the same?
Thanks!
----scan-data application----
CassandraFactory factory(argv[1], 9160);
tr1::shared_ptr<Cassandra> client(factory.create());
Keyspace *key_space = client->getKeyspace("campaign");
map<string, vector<Column> > mResult;
ColumnParent cp;
SlicePredicate sp;
string szStart, szEnd;
uint32_t uCount = 100; //try to retrieve 100 keys?
szStart =
"0000000000000000000000000000000000000000000000000000000000000000";
szEnd =
"1000000000000000000000000000000000000000000000000000000000000000";
cp.column_family = "test_col";
sp.__isset.slice_range = true;
sp.slice_range.start =
"0000000000000000000000000000000000000000000000000000000000000000";
sp.slice_range.finish =
"1000000000000000000000000000000000000000000000000000000000000000";
sp.slice_range.count = 100;
try {
mResult = key_space->getRangeSlice(cp, sp, szStart, szEnd,
uCount); //by libcassandra, mainly invoking get_range_slice()
/* then iterate the result and output */
}
}
} catch (org::apache::cassandra::InvalidRequestException &ire) {
cout << ire.why << endl;
delete key_space;
return 1;
}
return 0;
--
Kevin Yuan
www.yuan-shuai.info
