Maybe schema disagreement? Run nodetool describecluster to discover
Carlos Alonso | Software Engineer | @calonso <https://twitter.com/calonso> On 13 November 2015 at 11:14, Rajesh Radhakrishnan < rajesh.radhakrish...@phe.gov.uk> wrote: > > Hi, > > I am using Cassandra 2.1.5 in a cluster of two nodes (running CentOS) and > using Python driver to connect to Cassandra. > My Python code snippet is show here: > > > #------------------------------------------------------------------------------------------------------------------- > import time, os, datetime, keyword > import uuid > from cassandra.cluster import Cluster > import os.path, sys > .... > from cassandra.auth import PlainTextAuthProvider > .... > auth_provider = PlainTextAuthProvider(username, password) > cluster = Cluster([node1,node2],auth_provider=auth_provider) > session = cluster.connect(); > > session.execute("CREATE table IF NOT EXISTS test.iau (" > "id uuid, " > "sample_id text, " > "PRIMARY KEY (sample_id) )"); > > print " \n created the table" > #-------- > > sqlInsertSampleIdUid = "INSERT INTO test.iau (id, sample_id) > VALUES ("+str(uuid.uuid1())+",'sample123')" > session.execute(sqlInsertSampleIdUid) > print " \n Inserted main ids into the table" > #------- > > colNames > =['col1','col2','col3','col4','col5','col6','col7','col8','col9'] > > for colName in colNames : > > sqlAlterStatement1 = " ALTER TABLE test.iau ADD "+colName+" > text" > print sqlAlterStatement1 > session.execute(sqlAlterStatement1) > sqlAlterStatement1 = None > > print " Altered tables :: " > # ---------------------------------------- > count = 0 > for colName in colNames : > count = count +1 > sqlUpdateGeneDetection = " UPDATE test.iau SET "+colName+" = > '"+str(count)+"' WHERE sample_id = 'sample123'" > session.execute(sqlUpdateGeneDetection) > sqlUpdateGeneDetection = None > > print " Updated tables :: " > session.cluster.shutdown() > .... > > #------------------------------------------------------------------------------------------------------------------- > > Very rarely this code works, but most of the time it fails when it reach > ALTER statement. > FYI, I tried preparedstatement with binding in INSERT, UPDATE statements > too. > > The error with output is shown here: > > #------ > created the table > > Inserted main ids into the table > ALTER TABLE test.iau ADD col1 text > ALTER TABLE test.iau ADD col2 text > ALTER TABLE test.iau ADD col3 text > ALTER TABLE test.iau ADD col4 text > ALTER TABLE test.iau ADD col5 text > ALTER TABLE test.iau ADD col6 text > ALTER TABLE test.iau ADD col7 text > ALTER TABLE test.iau ADD col8 text > ALTER TABLE test.iau ADD col9 text > E > ====================================================================== > > ---------------------------------------------------------------------- > Traceback (most recent call last): > File "UnitTests.py", line 313, in test_insert_data > session.execute(sqlAlterStatement1) > File "/usr/local/lib/python2.7/site-packages/cassandra/cluster.py", line > 1405, in execute > result = future.result(timeout) > File "/usr/local/lib/python2.7/site-packages/cassandra/cluster.py", line > 2976, in result > raise self._final_exception > InvalidRequest: code=2200 [Invalid query] message="Invalid column name > col9 because it conflicts with an existing column" > > ---------------------------------------------------------------------- > Ran 1 test in 9.856s > #------ > > But when I checked the table using CQL col9 is not there. > > Is there' schema' refresh issue or is it bug in Cassandra 2.1.5? > > Thank you. > Kind regards > Rajesh R > > > > ************************************************************************** > The information contained in the EMail and any attachments is confidential > and intended solely and for the attention and use of the named > addressee(s). It may not be disclosed to any other person without the > express authority of Public Health England, or the intended recipient, or > both. If you are not the intended recipient, you must not disclose, copy, > distribute or retain this message or any part of it. This footnote also > confirms that this EMail has been swept for computer viruses by > Symantec.Cloud, but please re-sweep any attachments before opening or > saving. http://www.gov.uk/PHE > ************************************************************************** >
