I sent this email a little early, the error I get is:
 
Request did not complete within rpc_timeout.
 
If I merely repeat the same query I get:
 
cqlsh:my_dw> select count(*) from MyCF limit 70000;
TSocket read 0 bytes
cqlsh:my_dw> select count(*) from MyCF limit 70000;
Traceback (most recent call last):
  File "/usr/bin/cqlsh", line 1001, in perform_statement_untraced
    self.cursor.execute(statement, decoder=decoder)
  File "/usr/share/cassandra/lib/cql-internal-only-1.4.0.zip/cql-1.4.0/cql/cursor.py", line 80, in execute
    response = self.get_response(prepared_q, cl)
  File "/usr/share/cassandra/lib/cql-internal-only-1.4.0.zip/cql-1.4.0/cql/thrifteries.py", line 77, in get_response
    return self.handle_cql_execution_errors(doquery, compressed_q, compress, cl)
  File "/usr/share/cassandra/lib/cql-internal-only-1.4.0.zip/cql-1.4.0/cql/thrifteries.py", line 96, in handle_cql_execution_errors
    return executor(*args, **kwargs)
  File "/usr/share/cassandra/lib/cql-internal-only-1.4.0.zip/cql-1.4.0/cql/cassandra/Cassandra.py", line 1782, in execute_cql3_query
    self.send_execute_cql3_query(query, compression, consistency)
  File "/usr/share/cassandra/lib/cql-internal-only-1.4.0.zip/cql-1.4.0/cql/cassandra/Cassandra.py", line 1793, in send_execute_cql3_query
    self._oprot.trans.flush()
  File "/usr/share/cassandra/lib/thrift-python-internal-only-0.7.0.zip/thrift/transport/TTransport.py", line 293, in flush
    self.__trans.write(buf)
  File "/usr/share/cassandra/lib/thrift-python-internal-only-0.7.0.zip/thrift/transport/TSocket.py", line 117, in write
    plus = self.handle.send(buff)
error: [Errno 32] Broken pipe
 
I then lose C* and need to restart its service to reconnect.
 
Does that mean I have an underpowered machine?
 
Sent: Tuesday, June 11, 2013 10:02 AM
Subject: Unable to count records of a column family with 210 columns x 500K rows
 
Hello,
 
I am unable to count records using cqlsh (e.g.  select count(*) from MyCF limit 50000;)
I have a column family with 210 columns x 500K rows. The row length is 40K chars.
The same issue is with any other large CF.