This is the second part of our two-part article series devoted to Elasticsearch monitoring. The heading of this article refers to Dante Alighieri’s “Inferno”, in which Dante offers a tour through the nine increasingly terrifying levels of hell. Our journey into Elasticsearch monitoring was also filled with hardships, but we have overcome them and found solutions for each case.

We already wrote about monitoring posgresql queries, at the time we thought that we completely understood how PostgreSQL works with various server resources. Working regularly with the statistics of PostgreSQL queries, we noticed some anomalies and decided to dig a bit deeper for better understanding. Through this process, we found that while the behavior of postreSQL is kind of strange at first glance (or at least very peculiar), the clarity of its source code is quite admirable.