Monitor your hardware and services.
Recently I have encountered an error I wasn't too familiar with how to resolve, working with the ELK Stack. This specific error is the "[circuit_breaking_exception] [parent] Data too large, data for [<http_request>]". It is not directly visible where the error originates from, but with some sleuthing I discovered that it is caused by Elasticsearch preventing some requests from executing to avoid possible out of memory errors, as detailed in Elasticsearch Circuit Breaker documentation.Read more
In modern network infrastructures, there are a lot of sources of data, that can be of interest for collection and analysis, to see if possible suspicious activity is present in the network. More often than not, this data is collected and send to a Security Information and Event Management (SIEM) tool, running on the network, where it can be processed and reviewed by domain specialists.Read more
Managing big networks can be quite complicated- many inbound and outbound requests, network traffic, email correspondence and other activities that need to be monitored. It is quite easy for an attacker to obfuscate his actions, when we are confronted with large amounts of network data to analyze. Luckily there are ways to aggregate all this data and store it so it can be reviewed and hopefully discover any abnormal activity. Of course, I am talking about the use of a Security Information and Event Management (SIEM) framework. One such framework that has gained a lot of popularity, because of its modularity and open-source nature, is the ElasticSearch/Logstash/Kibana framework.Read more