# Catch Memcached Filter exceptions **URL:** \ **Category:** Logstash\ **Created:** [April 3, 2020, 3:35pm UTC](https://discuss.elastic.co/t/catch-memcached-filter-exceptions/226432 "2020-04-03T15:35:56Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Djamox](https://avatars.discourse-cdn.com/v4/letter/d/ce7236/32.png) [@Djamox](https://discuss.elastic.co/u/Djamox)\ **Post date:** [April 3, 2020, 3:35pm UTC](https://discuss.elastic.co/t/catch-memcached-filter-exceptions/226432/1 "2020-04-03T15:35:56Z")
Hi, I'm trying to connect to a memcached server via the filter Memcached. The problem is that the pipeline failed if the server is not available, and it is not acceptable. I couldn't find anything to handler failure so I tried to do it with a Ruby filter (it is the first time that I write something in Ruby so I do not know the language) : ```auto ruby { code => " require 'dalli' options = { :expires_in => 0 } Dalli::Client.new(['server:11211'], options).tap do |client| client.alive! end " } if '_rubyexception' not in [tags] { memcached { hosts => ["server:11211"] get => {"domain-%{[url][domain]}" => "[misp_src]"} } if ![misp_src] { mutate { add_field => {"[misp_src]" => "none"} } } } else{ mutate { add_field => {"[misp_src]" => "none"} } } ``` I have the following errors in Logstash docker logs : ``` [2020-04-03T15:04:41,953][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available [2020-04-03T15:04:41,953][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available [2020-04-03T15:04:41,961][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available W, [2020-04-03T15:04:42.074478 #1] WARN -- : server:11211 failed (count: 0) Timeout::Error: IO timeout: {:host=>"server", :port=>11211, :down_retry_delay=>60, :socket_timeout=>2.0, :socket_max_failures=>2, :socket_failure_delay=>0.01, :value_max_bytes=>1048576, :error_when_over_max_size=>false, :compressor=>Dalli::Compressor, :compression_min_size=>1024, :compression_max_size=>false, :serializer=>Marshal, :keepalive=>true, :sndbuf=>nil, :rcvbuf=>nil} [2020-04-03T15:04:42,086][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available W, [2020-04-03T15:04:42.106821 #1] WARN -- : server:11211 failed (count: 0) Timeout::Error: execution expired W, [2020-04-03T15:04:42.117425 #1] WARN -- : server:11211 failed (count: 0) Timeout::Error: execution expired [2020-04-03T15:04:42,120][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available W, [2020-04-03T15:04:42.128311 #1] WARN -- : server:11211 failed (count: 0) Timeout::Error: execution expired [2020-04-03T15:04:42,128][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available W, [2020-04-03T15:04:42.133284 #1] WARN -- : server:11211 failed (count: 0) Timeout::Error: execution expired [2020-04-03T15:04:42,139][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available [2020-04-03T15:04:42,144][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available W, [2020-04-03T15:04:42.145689 #1] WARN -- : server:11211 failed (count: 0) Timeout::Error: execution expired W, [2020-04-03T15:04:42.145865 #1] WARN -- : server:11211 failed (count: 0) Timeout::Error: execution expired W, [2020-04-03T15:04:42.146935 #1] WARN -- : server:11211 failed (count: 0) Timeout::Error: execution expired [2020-04-03T15:04:42,156][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available [2020-04-03T15:04:42,157][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available [2020-04-03T15:04:42,157][ERROR][logstash.filters.ruby] Ruby exception occurred: No server available W, [2020-04-03T15:04:42.158384 #1] WARN -- : server:11211 failed (count: 0) Timeout::Error: execution expired ``` Moreover, when a lauch the pipeline, the memcached server seems to be overloaded. Without the Ruby code (just the memcached filter), it works well but I don't handle exception. Thanks for any help, Maxime ---
**Author:** ![Badger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/badger/32/25190_2.png) [@Badger](https://discuss.elastic.co/u/Badger)\ **Post date:** [April 3, 2020, 4:02pm UTC](https://discuss.elastic.co/t/catch-memcached-filter-exceptions/226432/2 "2020-04-03T16:02:13Z")
The memcached filter [connects when it is initialized](https://github.com/logstash-plugins/logstash-filter-memcached/blob/1e85cf7e2662178ce4a21f589eefb052625fed01/lib/logstash/filters/memcached.rb#L80), not when it processes an event. It never attemps to reconnect, which is a [known issue](https://github.com/logstash-plugins/logstash-filter-memcached/issues/23). Your approach might work to avoid calling a memcached filter that failed to connect, but the logs are going to be noisy unless you [catch the exception](https://github.com/logstash-plugins/logstash-filter-memcached/blob/1e85cf7e2662178ce4a21f589eefb052625fed01/lib/logstash/filters/memcached.rb#L153) and add a tag to the event (i.e. set your own tag, do not rely on \_rubyexception). ---
**Author:** ![Djamox](https://avatars.discourse-cdn.com/v4/letter/d/ce7236/32.png) [@Djamox](https://discuss.elastic.co/u/Djamox)\ **Post date:** [April 6, 2020, 7:08am UTC](https://discuss.elastic.co/t/catch-memcached-filter-exceptions/226432/3 "2020-04-06T07:08:43Z")
Thanks for the answer. I understand better why the memcached server is overloaded with the ruby filter : because logstash will try to connect for each event whereas, with the memcached filter, the connection happens once. So thas it means that the if a value is set in memecached server after logstash tried to connect, it will never be seen by the filter ? Moreover, my problem is that I need sommething that prevent logstash from crashing at start if the memcached server is down. Is there something possible to do that ? ---
**Author:** ![Badger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/badger/32/25190_2.png) [@Badger](https://discuss.elastic.co/u/Badger)\ **Post date:** [April 6, 2020, 2:18pm UTC](https://discuss.elastic.co/t/catch-memcached-filter-exceptions/226432/4 "2020-04-06T14:18:15Z")
> [@Djamox](#): > > So thas it means that the if a value is set in memecached server after logstash tried to connect, it will never be seen by the filter ? I see no reason to believe that. I woud expect that if the cache is updated the old connection will see the new data. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [May 4, 2020, 2:22pm UTC](https://discuss.elastic.co/t/catch-memcached-filter-exceptions/226432/5 "2020-05-04T14:22:18Z")
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