UnsupportedOperationException (List#add) in NestedMultiOutput

[zapl]

The following started to happen when upgrading from 4.3.3 to 4.4.0:

org.springframework.data.redis.RedisSystemException: Redis exception; nested exception is com.lambdaworks.redis.RedisException: java.lang.UnsupportedOperationException
    at org.springframework.data.redis.connection.lettuce.LettuceExceptionConverter.convert(LettuceExceptionConverter.java:70)
    at org.springframework.data.redis.connection.lettuce.LettuceExceptionConverter.convert(LettuceExceptionConverter.java:41)
    at org.springframework.data.redis.PassThroughExceptionTranslationStrategy.translate(PassThroughExceptionTranslationStrategy.java:37)
    at org.springframework.data.redis.FallbackExceptionTranslationStrategy.translate(FallbackExceptionTranslationStrategy.java:37)
    at org.springframework.data.redis.connection.lettuce.LettuceConnection.convertLettuceAccessException(LettuceConnection.java:330)
    at org.springframework.data.redis.connection.lettuce.LettuceConnection.evalSha(LettuceConnection.java:3115)
    at org.springframework.data.redis.connection.DefaultStringRedisConnection.evalSha(DefaultStringRedisConnection.java:1429)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.data.redis.core.CloseSuppressingInvocationHandler.invoke(CloseSuppressingInvocationHandler.java:57)
    at com.sun.proxy.$Proxy7.evalSha(Unknown Source)
    at org.springframework.data.redis.core.script.DefaultScriptExecutor.eval(DefaultScriptExecutor.java:81)
    at org.springframework.data.redis.core.script.DefaultScriptExecutor$1.doInRedis(DefaultScriptExecutor.java:71)
    at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:207)
    at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:169)
    at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:157)
    at org.springframework.data.redis.core.script.DefaultScriptExecutor.execute(DefaultScriptExecutor.java:60)
    at org.springframework.data.redis.core.script.DefaultScriptExecutor.execute(DefaultScriptExecutor.java:54)
    at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:300)
    at com.foo.LettuceTest.exec(LettuceTest.java:24)
    at com.foo.LettuceTest.test(LettuceTest.java:33)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: com.lambdaworks.redis.RedisException: java.lang.UnsupportedOperationException
    at com.lambdaworks.redis.LettuceFutures.await(LettuceFutures.java:130)
    at com.lambdaworks.redis.LettuceFutures.awaitOrCancel(LettuceFutures.java:96)
    at com.lambdaworks.redis.FutureSyncInvocationHandler.handleInvocation(FutureSyncInvocationHandler.java:61)
    at com.lambdaworks.redis.internal.AbstractInvocationHandler.invoke(AbstractInvocationHandler.java:80)
    at com.sun.proxy.$Proxy4.evalsha(Unknown Source)
    at org.springframework.data.redis.connection.lettuce.LettuceConnection.evalSha(LettuceConnection.java:3113)
    ... 40 more
Caused by: java.lang.UnsupportedOperationException
    at java.util.AbstractList.add(AbstractList.java:148)
    at java.util.AbstractList.add(AbstractList.java:108)
    at com.lambdaworks.redis.output.NestedMultiOutput.set(NestedMultiOutput.java:52)
    at com.lambdaworks.redis.protocol.RedisStateMachine.safeSet(RedisStateMachine.java:429)
    at com.lambdaworks.redis.protocol.RedisStateMachine.decode(RedisStateMachine.java:202)
    at com.lambdaworks.redis.protocol.CommandHandler.decode(CommandHandler.java:313)
    at com.lambdaworks.redis.protocol.CommandHandler.decode(CommandHandler.java:257)
    at com.lambdaworks.redis.protocol.CommandHandler.channelRead(CommandHandler.java:241)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
    at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
    at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1294)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342)
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:911)
    at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131)
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:645)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:580)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:497)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459)
    at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:131)
    at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138)
    at java.lang.Thread.run(Thread.java:748)

The exception is triggered by the following test

public class LettuceTest {

    private static final String SCRIPT =
            "if redis.call(\"HEXISTS\",KEYS[1],ARGV[1]) ~= 1 then\n" +
            " return nil\n" +
            "end\n" +
            "if redis.call(\"EXISTS\",redis.call(\"HGET\",KEYS[1],ARGV[1])) ~= 1 then\n" +
            " return nil\n" +
            "end\n" +
            "return redis.call(\"HGETALL\",KEYS[1])";
    private static final RedisScript<List> script = new DefaultRedisScript<>(SCRIPT, List.class);
    public static List<?> exec(StringRedisTemplate redis, String hashKey, String fieldKey) {
        return redis.execute(script, Collections.singletonList(hashKey), fieldKey);
    }

    @Test
    public void test() {
        LettuceConnectionFactory connectionFactory = new LettuceConnectionFactory();
        connectionFactory.afterPropertiesSet();
        StringRedisTemplate template = new StringRedisTemplate(connectionFactory);
        template.afterPropertiesSet();
        exec(template, "foo", "bar");
    }
}

Environment:

• SpringBoot 1.5.4
• Lettuce 4.4.0
  • netty 4.0.49.Final
• Redis 3.2.9

[mp911de]

~Duplicate of #587.~

[zapl]

Unlike #587, it's com.lambdaworks.redis.output.NestedMultiOutput.set(NestedMultiOutput.java:52) that modifies the List. Is there a workaround / am I doing something wrong?

[mp911de]

Thanks for your response, my bad, I assumed it's the same behavior without digging into the details. That's clearly a bug in Lettuce.

[mp911de]

The problem was that the output required array responses. Your script did not respond with an array but a single element. Previously, NestedMultiOutput also accepted non-array responses. The fix falls back to the original behavior.