# FileBeat client failed to connect **URL:** https://discuss.elastic.co/t/filebeat-client-failed-to-connect/47745 **Category:** Beats **Created:** [April 19, 2016, 5:32am UTC](https://discuss.elastic.co/t/filebeat-client-failed-to-connect/47745 "2016-04-19T05:32:31Z") **Posts on this page:** 1 **Showing post:** 5
### Author: ![steffens](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/steffens/32/79630_2.png) [@steffens](https://discuss.elastic.co/u/steffens) #### Post date: [April 21, 2016, 12:51pm UTC](https://discuss.elastic.co/t/filebeat-client-failed-to-connect/47745/5 "2016-04-21T12:51:45Z")
1. Have you got some log messages from logstash? If logstash figures it's 'overloaded' it will not accept connections for N seconds. Logstash output in beats has default of 30s and it seem connection could not be made within this amount of seconds. With 30 workers in total, a subset of workers might be connected though? Have you checked with netstat how many connections are established? 2. this filebeat config as is doesn't really make use of load-balancing. No need to have a total of 30 workers pushing to logstash. By default filebeat will push to one worker only and wait for ACK before pushing to another worker. To have load-balancing work properly in filebeat there are to options: Option 1: Enable `publish_async: true` in filebeat section. This option will create batches and publish fully asynchronous. CPU/memory usage will be much increased Option 2: Increase spooler\_size to be a multiple to bulk\_max\_size in logstash output. By default both values are 2048. Having spooler\_size = 30\*bulk\_max\_size, the batch of lines created by spooler is devided into 30 mini-batches to be forwarded by logstash output with full load-balancing. We still have to wait for all logstash instances to ACK the publish request before sending the next batch. Throughput might be a little less in comparison to `publish_async: true`, but so might be memory usage. --- _[View the full topic](https://discuss.elastic.co/t/filebeat-client-failed-to-connect/47745)._