[
https://issues.apache.org/jira/browse/CASSANDRA-9077?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14388054#comment-14388054
]
Jeff Jirsa edited comment on CASSANDRA-9077 at 3/31/15 5:47 AM:
----------------------------------------------------------------
The underlying problem is that
o.a.c.db.composites.AbstractCellNameType.CQL3RowOfSparse getMultiCellColumn()
can return null (if collection==null), which happens if/when you delete the
list.
A very similar NPE would be thrown if you tried to update to set a list element
by index once the list was deleted:
{noformat}
cqlsh:test2> update t set l[0] = '1' where id='user';
ServerError: <ErrorMessage code=0000 [Server error]
message="java.lang.NullPointerException">
{noformat}
{noformat}
ERROR [SharedPool-Worker-1] 2015-03-30 22:22:32,682 QueryMessage.java:132 -
Unexpected error during query
java.lang.NullPointerException: null
at
org.apache.cassandra.cql3.Lists$SetterByIndex.execute(Lists.java:345)
~[main/:na]
at
org.apache.cassandra.cql3.statements.UpdateStatement.addUpdateForKey(UpdateStatement.java:111)
~[main/:na]
at
org.apache.cassandra.cql3.statements.UpdateStatement.addUpdateForKey(UpdateStatement.java:58)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.getMutations(ModificationStatement.java:643)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.executeWithoutCondition(ModificationStatement.java:475)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.execute(ModificationStatement.java:461)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.processStatement(QueryProcessor.java:234)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:261)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:246)
~[main/:na]
at
org.apache.cassandra.transport.messages.QueryMessage.execute(QueryMessage.java:119)
~[main/:na]
at
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:475)
~[main/:na]
at
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:371)
~[main/:na]
at
io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext.access$700(AbstractChannelHandlerContext.java:32)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext$8.run(AbstractChannelHandlerContext.java:324)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
~[na:1.7.0_25]
at
org.apache.cassandra.concurrent.AbstractTracingAwareExecutorService$FutureTask.run(AbstractTracingAwareExecutorService.java:164)
~[main/:na]
at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105)
~[main/:na]
at java.lang.Thread.run(Thread.java:724) ~[na:1.7.0_25]
ERROR [SharedPool-Worker-1] 2015-03-30 22:22:32,683 ErrorMessage.java:329 -
Unexpected exception during request
java.lang.NullPointerException: null
at
org.apache.cassandra.cql3.Lists$SetterByIndex.execute(Lists.java:345)
~[main/:na]
at
org.apache.cassandra.cql3.statements.UpdateStatement.addUpdateForKey(UpdateStatement.java:111)
~[main/:na]
at
org.apache.cassandra.cql3.statements.UpdateStatement.addUpdateForKey(UpdateStatement.java:58)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.getMutations(ModificationStatement.java:643)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.executeWithoutCondition(ModificationStatement.java:475)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.execute(ModificationStatement.java:461)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.processStatement(QueryProcessor.java:234)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:261)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:246)
~[main/:na]
at
org.apache.cassandra.transport.messages.QueryMessage.execute(QueryMessage.java:119)
~[main/:na]
at
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:475)
~[main/:na]
at
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:371)
~[main/:na]
at
io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext.access$700(AbstractChannelHandlerContext.java:32)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext$8.run(AbstractChannelHandlerContext.java:324)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
~[na:1.7.0_25]
at
org.apache.cassandra.concurrent.AbstractTracingAwareExecutorService$FutureTask.run(AbstractTracingAwareExecutorService.java:164)
~[main/:na]
at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105)
~[main/:na]
at java.lang.Thread.run(Thread.java:724) ~[na:1.7.0_25]
{noformat}
There are two ways to fix this - could either
1) Check for null in Lists.java, and throw a new error trying to delete an
element from an empty list (or similarly, try to add an element at an index of
an empty list),
{noformat}
cqlsh:test2> INSERT INTO t (id, l, s) VALUES ('user', ['1'], {'1'}); DELETE l
FROM t WHERE id ='user'; DELETE l[0] FROM t WHERE id = 'user';
InvalidRequest: code=2200 [Invalid query] message="Attempt to delete from an
empty list"
cqlsh:test2> update t set l[0] = '1' where id='user';
InvalidRequest: code=2200 [Invalid query] message="Attempt to set an element on
a null list"
cqlsh:test2>
{noformat}
2) Make it return an actual empty list instead of null, in which case the
existing bounds checking works as intended:
{noformat}
cqlsh:test2> INSERT INTO t (id, l, s) VALUES ('user', ['1'], {'1'}); DELETE l
FROM t WHERE id ='user'; DELETE l[0] FROM t WHERE id = 'user';
InvalidRequest: code=2200 [Invalid query] message="List index 0 out of bound,
list has size 0"
cqlsh:test2> update t set l[0] = '1' where id='user';
InvalidRequest: code=2200 [Invalid query] message="List index 0 out of bound,
list has size 0"
cqlsh:test2>
{noformat}
Both patches attached. Leaving it to a reviewer to decide which is the right
approach (perhaps both?)
was (Author: jjirsa):
The underlying problem is that
o.a.c.db.composites.AbstractCellNameType.CQL3RowOfSparse getMultiCellColumn()
can return null (if collection==null), which happens if/when you delete the
list.
A very similar NPE would be thrown if you tried to update to set a list element
by index once the list was deleted:
{noformat}
cqlsh:test2> update t set l[0] = '1' where id='user';
ServerError: <ErrorMessage code=0000 [Server error]
message="java.lang.NullPointerException">
{noformat}
{noformat}
ERROR [SharedPool-Worker-1] 2015-03-30 22:22:32,682 QueryMessage.java:132 -
Unexpected error during query
java.lang.NullPointerException: null
at
org.apache.cassandra.cql3.Lists$SetterByIndex.execute(Lists.java:345)
~[main/:na]
at
org.apache.cassandra.cql3.statements.UpdateStatement.addUpdateForKey(UpdateStatement.java:111)
~[main/:na]
at
org.apache.cassandra.cql3.statements.UpdateStatement.addUpdateForKey(UpdateStatement.java:58)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.getMutations(ModificationStatement.java:643)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.executeWithoutCondition(ModificationStatement.java:475)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.execute(ModificationStatement.java:461)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.processStatement(QueryProcessor.java:234)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:261)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:246)
~[main/:na]
at
org.apache.cassandra.transport.messages.QueryMessage.execute(QueryMessage.java:119)
~[main/:na]
at
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:475)
~[main/:na]
at
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:371)
~[main/:na]
at
io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext.access$700(AbstractChannelHandlerContext.java:32)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext$8.run(AbstractChannelHandlerContext.java:324)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
~[na:1.7.0_25]
at
org.apache.cassandra.concurrent.AbstractTracingAwareExecutorService$FutureTask.run(AbstractTracingAwareExecutorService.java:164)
~[main/:na]
at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105)
~[main/:na]
at java.lang.Thread.run(Thread.java:724) ~[na:1.7.0_25]
ERROR [SharedPool-Worker-1] 2015-03-30 22:22:32,683 ErrorMessage.java:329 -
Unexpected exception during request
java.lang.NullPointerException: null
at
org.apache.cassandra.cql3.Lists$SetterByIndex.execute(Lists.java:345)
~[main/:na]
at
org.apache.cassandra.cql3.statements.UpdateStatement.addUpdateForKey(UpdateStatement.java:111)
~[main/:na]
at
org.apache.cassandra.cql3.statements.UpdateStatement.addUpdateForKey(UpdateStatement.java:58)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.getMutations(ModificationStatement.java:643)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.executeWithoutCondition(ModificationStatement.java:475)
~[main/:na]
at
org.apache.cassandra.cql3.statements.ModificationStatement.execute(ModificationStatement.java:461)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.processStatement(QueryProcessor.java:234)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:261)
~[main/:na]
at
org.apache.cassandra.cql3.QueryProcessor.process(QueryProcessor.java:246)
~[main/:na]
at
org.apache.cassandra.transport.messages.QueryMessage.execute(QueryMessage.java:119)
~[main/:na]
at
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:475)
~[main/:na]
at
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(Message.java:371)
~[main/:na]
at
io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:333)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext.access$700(AbstractChannelHandlerContext.java:32)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
io.netty.channel.AbstractChannelHandlerContext$8.run(AbstractChannelHandlerContext.java:324)
~[netty-all-4.0.23.Final.jar:4.0.23.Final]
at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
~[na:1.7.0_25]
at
org.apache.cassandra.concurrent.AbstractTracingAwareExecutorService$FutureTask.run(AbstractTracingAwareExecutorService.java:164)
~[main/:na]
at org.apache.cassandra.concurrent.SEPWorker.run(SEPWorker.java:105)
~[main/:na]
at java.lang.Thread.run(Thread.java:724) ~[na:1.7.0_25]
{noformat}
There are two ways to fix this - could either
1) Check for null in Lists.java, and throw a new error trying to delete an
element from an empty list (or similarly, try to add an element at an index of
an empty list),
{noformat}
cqlsh:test2> INSERT INTO t (id, l, s) VALUES ('user', ['1'], {'1'}); DELETE l
FROM t WHERE id ='user'; DELETE l[0] FROM t WHERE id = 'user';InvalidRequest:
code=2200 [Invalid query] message="Attempt to delete from an empty list"
cqlsh:test2> update t set l[0] = '1' where id='user';
InvalidRequest: code=2200 [Invalid query] message="Attempt to set an
element on a null list"
cqlsh:test2>
{noformat}
2) Make it return an actual empty list instead of null, in which case the
existing bounds checking works as intended:
{noformat}
cqlsh:test2> INSERT INTO t (id, l, s) VALUES ('user', ['1'], {'1'}); DELETE l
FROM t WHERE id ='user'; DELETE l[0] FROM t WHERE id = 'user';
InvalidRequest: code=2200 [Invalid query] message="List index 0 out of
bound, list has size 0"
cqlsh:test2> update t set l[0] = '1' where id='user';
InvalidRequest: code=2200 [Invalid query] message="List index 0 out of
bound, list has size 0"
cqlsh:test2>
{noformat}
Both patches attached. Leaving it to a reviewer to decide which is the right
approach (perhaps both?)
> NPE
> ---
>
> Key: CASSANDRA-9077
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9077
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Reporter: dan jatnieks
> Priority: Minor
> Attachments: 9077-stacktrace.log
>
>
> I am seeing an NPE on the latest 2.1 branch with this sequence of deletes
> from a list - first delete the entire list, then attempt to delete one
> element.
> I expected to see {{List index 0 out of bound, list has size 0}} but instead
> got an NPE.
> {noformat}
> ./bin/cqlsh
> Connected to Test Cluster at 127.0.0.1:9042.
> [cqlsh 5.0.1 | Cassandra 2.1.3-SNAPSHOT | CQL spec 3.2.0 | Native protocol v3]
> Use HELP for help.
> cqlsh> use frozen_collections ;
> cqlsh:frozen_collections> DROP TABLE IF EXISTS t;
> cqlsh:frozen_collections> CREATE TABLE t (id text PRIMARY KEY, l list<text>,
> s set<text>);
> cqlsh:frozen_collections> INSERT INTO t (id, l, s) VALUES ('user', ['1'],
> {'1'});
> cqlsh:frozen_collections>
> cqlsh:frozen_collections> DELETE l FROM t WHERE id ='user';
> cqlsh:frozen_collections> //INSERT INTO t (id, l) VALUES ('user', ['1']);
> cqlsh:frozen_collections> DELETE l[0] FROM t WHERE id = 'user';
> ServerError: <ErrorMessage code=0000 [Server error]
> message="java.lang.NullPointerException">
> cqlsh:frozen_collections>
> cqlsh:frozen_collections> DELETE s FROM t WHERE id ='user';
> cqlsh:frozen_collections> DELETE s['1'] FROM t WHERE id = 'user';
> {noformat}
> It appears the {{DELETE emails...}} directly followed by {{DELETE
> emails[0]...}} is the offending sequence. Either one alone works fine, as
> does adding an intervening insert/update.
> The same sequence performed on a Set rather than List works (as shown above).
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
