NullPointerException while getting partitions on NodeTopologyView.getMatchOrDefault(NodeTopologyView.java:94)

[rafadesu]

Bug Report

I found similar closed error reported here: #2243

Current Behavior

Stack trace

java.lang.NullPointerException: Cannot invoke "java.lang.CharSequence.length()" because "this.text" is null
	at java.base/java.util.regex.Matcher.getTextLength(Matcher.java:1769)
	at java.base/java.util.regex.Matcher.reset(Matcher.java:415)
	at java.base/java.util.regex.Matcher.<init>(Matcher.java:252)
	at java.base/java.util.regex.Pattern.matcher(Pattern.java:1134)
	at io.lettuce.core.cluster.topology.NodeTopologyView.getMatchOrDefault(NodeTopologyView.java:94)
	at io.lettuce.core.cluster.topology.NodeTopologyView.getClientCount(NodeTopologyView.java:85)
	at io.lettuce.core.cluster.topology.NodeTopologyView.<init>(NodeTopologyView.java:73)
	at io.lettuce.core.cluster.topology.NodeTopologyView.from(NodeTopologyView.java:109)
	at io.lettuce.core.cluster.topology.DefaultClusterTopologyRefresh.getNodeSpecificViews(DefaultClusterTopologyRefresh.java:229)
	at io.lettuce.core.cluster.topology.DefaultClusterTopologyRefresh.lambda$null$1(DefaultClusterTopologyRefresh.java:108)
	at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:646)
	at java.base/java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:482)
	at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:174)
	at io.netty.util.concurrent.DefaultEventExecutor.run(DefaultEventExecutor.java:66)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:833)

Input Code

Input Code

            try {
                client.reloadPartitions();
                partitions = clusterConnection.getPartitions();
                log.info("A final reload of partitions after failover is completed");
            } catch (Exception e) {
                log.error("Unable to reload partitions after failover is completed", e);
            }

where client is RedisClusterClient and clusterConnection is StatefulRedisClusterConnection<byte[], byte[]>

Expected behavior/code

I would hope for partitions to be returned without NPE.

Environment

• Lettuce version(s): 6.2.6.RELEASE
• Redis version: 3.5.66

Possible Solution

I don't have any other than retrying.

Additional context

N/A

[mp911de]

This doesn't look like a version 6.2.6 exception but rather as if there were many Lettuce versions on the class path. getMatchOrDefault is guarded against a null value when looking up the client count.

[rafadesu]

You are right... this seems more accurate with 6.1.10.RELEASE which we updated from.
My mvn dependency:tree is clearly indicated 6.2.6.RELEASE though...:

[INFO] |     +- io.lettuce:lettuce-core:jar:6.2.6.RELEASE:compile
[INFO] |  |  |  |  |  \- io.lettuce:lettuce-core:jar:6.2.6.RELEASE:compile
[INFO] |  |  +- io.lettuce:lettuce-core:jar:6.2.6.RELEASE:compile
[INFO] |  |  |  \- io.lettuce:lettuce-core:jar:6.2.6.RELEASE:compile

But it is clearly my mistake. This seems to be a NPE in an instance that didn't get updated yet to 6.2.6.RELEASE.

Please disregard this issue and accept my apologies.

[mp911de]

No worries, each report can turn out as bug.