Hello EveryOne,
The typical way of doing this would be to produce events with a field indicate whether the call was successful or not and then use Kibana to compute the success rate in a particular interval.
The events are created by Logstash based on the input configuration you've provided. Once you have events with the text listed above, use a grok or a dissect filter to extract pieces from the line into fields of their own. Please study the configuration examples in the Logstash documentation.
How to best visualize this is more of a Kibana question.
Send the events to Elasticsearch and use Kibana to visualize them.
For the last time: That's a Kibana question that you can ask in the Kibana group. You will not use Logstash to calculate the percentages.