[jira] [Created] (CASSANDRA-17047) Dropping a column can break queries until the schema is fully propagated (TAKE 2)

["Benjamin Lerer (Jira)" <ji...@apache.org>]

Benjamin Lerer created CASSANDRA-17047:
------------------------------------------

             Summary: Dropping a column can break queries until the schema is fully propagated (TAKE 2)
                 Key: CASSANDRA-17047
                 URL: https://issues.apache.org/jira/browse/CASSANDRA-17047
             Project: Cassandra
          Issue Type: Bug
            Reporter: Benjamin Lerer
            Assignee: Benjamin Lerer


With a table like:
{code}
CREATE TABLE ks.tbl (id int primary key, v1 int, v2 int, v3 int)
{code}

and we drop {{v2}}, we get this exception on the replicas which haven't seen the schema change:
{code}
ERROR [SharedPool-Worker-1] node2 2020-06-24 09:49:08,107 AbstractLocalAwareExecutorService.java:169 - Uncaught exception on thread Thread[SharedPool-Worker-1,5,node2]
java.lang.IllegalStateException: [ColumnDefinition{name=v1, type=org.apache.cassandra.db.marshal.Int32Type, kind=REGULAR, position=-1}, ColumnDefinition{name=v2, type=org.apache.cassandra.db.marshal.Int32Type, kind=REGULAR, position=-1}, ColumnDefinition{name=v3, type=org.apache.cassandra.db.marshal.Int32Type, kind=REGULAR, position=-1}] is not a subset of [v1 v3]
	at org.apache.cassandra.db.Columns$Serializer.encodeBitmap(Columns.java:546) ~[main/:na]
	at org.apache.cassandra.db.Columns$Serializer.serializeSubset(Columns.java:478) ~[main/:na]
	at org.apache.cassandra.db.rows.UnfilteredSerializer.serialize(UnfilteredSerializer.java:184) ~[main/:na]
	at org.apache.cassandra.db.rows.UnfilteredSerializer.serialize(UnfilteredSerializer.java:114) ~[main/:na]
	at org.apache.cassandra.db.rows.UnfilteredSerializer.serialize(UnfilteredSerializer.java:102) ~[main/:na]
	at org.apache.cassandra.db.rows.UnfilteredRowIteratorSerializer.serialize(UnfilteredRowIteratorSerializer.java:132) ~[main/:na]
	at org.apache.cassandra.db.rows.UnfilteredRowIteratorSerializer.serialize(UnfilteredRowIteratorSerializer.java:87) ~[main/:na]
...
{code}

Note that it doesn't matter if we {{SELECT *}} or {{SELECT id, v1}}

CASSANDRA-15899 tried to fix the problem when columns are dropped as well as when columns are added. Unfortunately the fix introduced an issue and had to be reverted in CASSANDRA-16735. 

If the scenario for ADDED columns is tricky, the original scenario for DROPPED columns can  be solved in a safe way at the {{ColumnFilter}} level. By consequence, I think that we should at least solve that scenario.

[~bdeggleston], [~samt], [~ifesdjeen] does it make sense to you?    




--
This message was sent by Atlassian Jira
(v8.3.4#803005)

---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscribe@cassandra.apache.org
For additional commands, e-mail: commits-help@cassandra.apache.org