Jeff Jirsa created CASSANDRA-11340:
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Summary: Speculative retry on system_auth tables can cause deadlock
Key: CASSANDRA-11340
URL: https://issues.apache.org/jira/browse/CASSANDRA-11340
Project: Cassandra
Issue Type: Bug
Reporter: Jeff Jirsa
Reproduced in at least 2.1.9.
It appears possible for queries against system_auth tables to trigger
speculative retry, which causes auth to block on traffic going off node. In
some cases, it appears possible for threads to become deadlocked, causing load
on the nodes to increase sharply. This happens even in clusters with RF of
system_auth == N, as all requests being served locally puts the bar for 99% SR
pretty low.
Incomplete stack trace below, but we haven't yet figured out what exactly is
blocking:
{code}
Thread 82291: (state = BLOCKED)
- sun.misc.Unsafe.park(boolean, long) @bci=0 (Compiled frame; information may
be imprecise)
- java.util.concurrent.locks.LockSupport.parkNanos(long) @bci=11, line=338
(Compiled frame)
-
org.apache.cassandra.utils.concurrent.WaitQueue$AbstractSignal.awaitUntil(long)
@bci=28, line=307 (Compiled frame)
- org.apache.cassandra.utils.concurrent.SimpleCondition.await(long,
java.util.concurrent.TimeUnit) @bci=76, line=63 (Compiled frame)
- org.apache.cassandra.service.ReadCallback.await(long,
java.util.concurrent.TimeUnit) @bci=25, line=92 (Compiled frame)
-
org.apache.cassandra.service.AbstractReadExecutor$SpeculatingReadExecutor.maybeTryAdditionalReplicas()
@bci=39, line=281 (Compiled frame)
- org.apache.cassandra.service.StorageProxy.fetchRows(java.util.List,
org.apache.cassandra.db.ConsistencyLevel) @bci=175, line=1338 (Compiled frame)
- org.apache.cassandra.service.StorageProxy.readRegular(java.util.List,
org.apache.cassandra.db.ConsistencyLevel) @bci=9, line=1274 (Compiled frame)
- org.apache.cassandra.service.StorageProxy.read(java.util.List,
org.apache.cassandra.db.ConsistencyLevel,
org.apache.cassandra.service.ClientState) @bci=57, line=1199 (Compiled frame)
-
org.apache.cassandra.cql3.statements.SelectStatement.execute(org.apache.cassandra.service.pager.Pageable,
org.apache.cassandra.cql3.QueryOptions, int, long,
org.apache.cassandra.service.QueryState) @bci=35, line=272 (Compiled frame)
-
org.apache.cassandra.cql3.statements.SelectStatement.execute(org.apache.cassandra.service.QueryState,
org.apache.cassandra.cql3.QueryOptions) @bci=105, line=224 (Compiled frame)
- org.apache.cassandra.auth.Auth.selectUser(java.lang.String) @bci=27,
line=265 (Compiled frame)
- org.apache.cassandra.auth.Auth.isExistingUser(java.lang.String) @bci=1,
line=86 (Compiled frame)
-
org.apache.cassandra.service.ClientState.login(org.apache.cassandra.auth.AuthenticatedUser)
@bci=11, line=206 (Compiled frame)
-
org.apache.cassandra.transport.messages.AuthResponse.execute(org.apache.cassandra.service.QueryState)
@bci=58, line=82 (Compiled frame)
-
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(io.netty.channel.ChannelHandlerContext,
org.apache.cassandra.transport.Message$Request) @bci=75, line=439 (Compiled
frame)
-
org.apache.cassandra.transport.Message$Dispatcher.channelRead0(io.netty.channel.ChannelHandlerContext,
java.lang.Object) @bci=6, line=335 (Compiled frame)
-
io.netty.channel.SimpleChannelInboundHandler.channelRead(io.netty.channel.ChannelHandlerContext,
java.lang.Object) @bci=17, line=105 (Compiled frame)
-
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(java.lang.Object)
@bci=9, line=333 (Compiled frame)
-
io.netty.channel.AbstractChannelHandlerContext.access$700(io.netty.channel.AbstractChannelHandlerContext,
java.lang.Object) @bci=2, line=32 (Compiled frame)
- io.netty.channel.AbstractChannelHandlerContext$8.run() @bci=8, line=324
(Compiled frame)
- java.util.concurrent.Executors$RunnableAdapter.call() @bci=4, line=511
(Compiled frame)
-
org.apache.cassandra.concurrent.AbstractTracingAwareExecutorService$FutureTask.run()
@bci=5, line=164 (Compiled frame)
- org.apache.cassandra.concurrent.SEPWorker.run() @bci=87, line=105
(Interpreted frame)
- java.lang.Thread.run() @bci=11, line=745 (Interpreted frame)
{code}
In a cluster with many connected clients (potentially thousands), a
reconnection flood (for example, restarting all at once) is likely to trigger
this bug. However, it is unlikely to be seen in normal operation.
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