Logstash shipper events stuck at redis

Kindly verify my redis input configuration for logstash indexer, below is the input config details which worked for some time later it is not working.
I have upgraded to logstash 2.1.1 from logstash 1.4.2

input{ redis { host => "host" port => "7000" data_type => "list" key => "syslog" } }

Well, what happens? Is there an error or warning message in the logs? Do you get additional clues if you crank up the log level with --verbose or --debug?

I couldn't find any log level in the settings, could you please tell me how to find current logging level

The log level is set via command-line options, listed above. Without those options you get the default log level.

I am getting below message when i use --verbose.

Flushing buffer at interval {:instance=>"LogStash::Outputs::ElasticSearch::Buffer:0x7b452a3e operations_mutex=Mutex:0x7582db26>, max_size=500, operations_lock=Java::JavaUtilConcurrentLocks::ReentrantLock:0x71bd414e>, submit_proc=Proc:0x66f9096e/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-output-elasticsearch-2.2.0-java/lib/logstash/outputs/elasticsearch/common.rb:55>, logger=#<Cabin::Channel:0x541a57c metrics=Cabin::Metrics:0x1eed23ab metrics_lock=#Mutex:0x54902e52>, metrics={}, channel=Cabin::Channel:0x541a57c ...>>, subscriber_lock=Mutex:0x7a0cefd7>, level=:info, subscribers={12590=>Cabin::Outputs::IO:0x5e94a32 io=<IO:fd 1>, lock=Mutex:0x50de1663>}, @data={}>, last_flush=2016-02-02 04:07:35 -0500, @flush_interval=1, stopping=#Concurrent::AtomicBoolean:0x4db129f8>, buffer=[], flush_thread=Thread:0x49a69456 run>>", :interval=>1, :level=>:info}

Surely that's not the only thing you get with verbose logging. Anything in there that hints at a problem?

Apart from above message, getting redis warning.

Redis connection problem {:exception=>#Redis::CommandError: CROSSSLOT Keys in request don't hash to the same slot>, :level=>:warn}