Sometimes when we ssh to Linux box, we get this error “WARNING: Your password has expired.” You must change your password now and login again! Changing password for user ocp. Changing password for ocp.” What does “WARNING: Your password has…
Cassandra uses data partitions to distribute data to each node. Partitions are based on the partition keys. Partition function(partition key) = token number. Apache Cassandra Data Partitions Apache Cassandra, a NoSQL database, belongs to the big data family of applications…
Apache Cassandra supports two kinds of backup strategies. A snapshot is a copy of a table’s SSTable files at a given time, created via hard links. The DDL to create the table is stored as well. Snapshots may be created…
Cassandra timeout issue is a complex issue. Today we will review what read timeout mean in Cassandra and how to fix it. what does Read timeout mean in Cassandra cluster? A read request reached the coordinator, which initially believed that…
Rp_filter is short for reverse path filtering on Linux. We can use this to filter packets on Linux. Here are 5 common questions about rp_filter. What is reverse path filtering? Reverse path filtering is a mechanism adopted by the Linux…
Apache Cassandra cluster is a distributed system. Monitoring this cluster is not an easy task. There are a few monitoring tools for Cassandra in the market. Most of them are commercial products. Today we are going to use open source…
NFS performance is important for the production environment. In this tutorial, we will review how to use DD command to test local storage and NFS storage performance. Test nfs storage performance on Linux There are some differences between each testing…
A system is having a single core, and if there is a single process consuming all the CPU Time, then CPU utilization will show 100% utilization. But in case of multi core systems it is not necessary that all the…
Linux monitoring is not an easy task for Linux admins. Luckily we have open-source software to monitor these metrics now. Today we are going to learn Linux metrics we can monitor using this monitor bundle Telegraf We can monitor the…
actimeo is a common NFS mount option in Linux. actimeo=0 can make a big performance difference in the production environment. What does actimeo mean in nfs mount? The “actimeo=0” option means turn attribute caching off. The actimeo option actually makes…
