Netdata’s Cassandra collector documentation explains how to set it up to collect metrics automatically. Once you have followed the instructions in the docs and have installed and configured Netdata on the Cassandra cluster you are ready to start monitoring and troubleshooting.
Database bloat is disk space that was used by a table or index and is available for reuse by the database but has not been reclaimed. Bloat is created when deleting or updating tables and indexes. Here's how to deal with it!
What are the important Cassandra metrics to monitor and how to monitor them.
We often hear the term load used to describe the state of a server or a device, but we're here to tell you what it means, precisely, and how to monitor it.
The most important part of disk usage monitoring is to check the utilization of each filesystem and each mount point which can reveal existing or impending issues with the storage space on your infrastructure.
The life of a sysadmin or SRE is often difficult, but occasionally very simple things can make a huge difference. Basic monitoring of your systemd services is one of those simple things, which we sometimes overlook. The simplest question one would want to know is if the thing that’s supposed to be running is actually running at all. If you use systemd services, you can guarantee an answer to that question within minutes using Netdata.
Redis is designed to be fast. In most cases, it is. However, there are times when Redis may be slow, due to network issues, disk latency, or other factors. When this happens, it is important to be able to detect the slow down and investigate the cause. Latency is the maximum delay between the time a client issues a command and the time the reply to the command is received by the client. Redis has strict requirements on average and worst case latency.
Netdata just launched a Pandas collector. Pandas is a de-facto standard in reading and processing most types of structured data in Python so if you have some csv/json/xml data, either locally or via some HTTP endpoint, containing metrics you’d like to monitor, chances are you can now easily do this by leveraging the Pandas collector without having to develop your own custom collector as you might have in the past.
Web servers are among the most important components in modern IT infrastructures. They host the websites, web services, and web applications that we use on a daily basis. Social networking, media streaming, software as a service (SaaS), and other activities wouldn’t be possible without the use of web servers. And with the advent of cloud computing and the movement of more services online, web servers and their monitoring are only becoming more important.
The HTTP protocol has become the de facto standard application layer protocol of the internet. From publicly available web sites and APIs to “inter-process” communications in REST based microservice architectures or large Service Oriented Architectures based on SOAP, you find HTTP being used again and again, due to its simplicity and our familiarity with it. How many protocols can you name that have memes for their status codes?
DNS (Domain Name System) servers translate standard language web addresses to their actual IP addresses for network access. DNS response time is the time it takes a Domain Name Server to receive the request for a domain name’s IP address, process it, and return the IP address to the browser or application requesting it. When it comes to DNS response times, the lower the better, and generally values less than 100ms are considered to be in the acceptable range (depending on the application).
High availability. This is what every monitoring tool needs to ensure that you never compromise on IT infrastructure visibility. On top of high availability, do you really want to enable all available features on your production system? It is important for the monitoring tool to have a low footprint on your CPU consumption and memory usage. Let’s dive deeper into the recommended way of configuring Netdata to ensure high availability and a low resource footprint through data replication.
Most sysadmins and developers have at some point used a few of the popular Linux networking commands or their Windows equivalents to answer the common questions of host reachability- that is, whether a host or service is reachable and how fast it responds. One of the simplest, common checks, is to simply ping a host to verify that it’s reachable from where you issue the command, and to see the total time it takes for the host to receive your request.
It is sometimes easy to get lost in the mountain of metrics and infinite number of dimensions when working with an infrastructure monitoring tool. Being able to filter metrics by label and visualize only what is relevant to the current scope of monitoring & troubleshooting, becomes absolutely crucial to the success of SREs, Sysadmins and DevOps professionals.
While working on improving the Netdata PostgreSQL collector, we were monitoring our production PostgreSQL instance and something caught our attention immediately. The rows fetched ratio seemed really, really low for one particular database… there were missing indexes in PostgreSQL! Rows fetched ratio is the percentage of rows that contain data needed to execute the query (rows fetched), out of the total number of rows scanned (rows returned).
