In this chapter, we've seen how to add some instrumentation in our microservices and at the web server level. We've also learned how to set up Graylog to centralize and use all the generated logs and performance metrics.

Graylog uses Elasticsearch to store all the data, and that choice offers fantastic search features that will make your life easier to look for what's going on. The ability to add alerts is also useful for being notified when something's wrong. But deploying Graylog should be considered carefully. An Elastic Search cluster is heavy to run and maintain once it has a lot of data.

For your metrics, time-series based systems such as ;InfluxDB (open source) from InfluxData (https://www.influxdata.com/) is a faster and lightweight alternative. But it's not meant to store raw logs and exceptions.

So if you just care about performance metrics and exceptions, maybe a good solution would be to use a combination of tools: Sentry for your exceptions and InfluxDB for tracking performances. In any case, as long as your applications and web servers generate logs and metrics via UDP, it makes it easier to move from one tool to another.

The next chapter will focus on another important aspect of microservices development: how to secure your APIs, offer some authentication solutions, and avoid fraud and abuse.