We can use the following steps to remove a datacenter in the Cassandra cluster. How long time it takes for a datacenter removal? On the bright side, the operation should be almost instantaneous (at least very quick), because this datacenter…
In Cassandra, data in a replica can become inconsistent with other replicas due to the distributed nature of the database. Node repair corrects the inconsistencies so that eventually all nodes have the same and most up-to-date data. It is an…
We can take a node out of the cluster with nodetool decommission to a live node, or nodetool removenode (to any other machine) to remove a dead one. This will assign the ranges the old node was responsible for to…
TIME WAIT state is a normal part of a TCP socket’s life cycle. It cannot and should not be avoided. TIME WAIT sockets may become an issue when there are tens of thousands active at any given time. Otherwise, smaller numbers of…
Many people choose free open source software to monitor Cassandra cluster to save cost. In our env, we use telegraf/Influxdb/Grafana to monitor Cassandra performance. This monitoring package is open source. We can download and use them for free. Use TIG…
Error message is the first step to troubleshoot Apache Cassandra issues. That can help us identify if the issue happens on client-side or server-side. Here are the 4 most common Cassandra issues below. Check Cassandra SyntaxError (client) This and other…
We need to add open source Apache node to dse cluster first. After the data sync is done, we can remove dse nodes. Here are the steps about how to add Apache nodes to dse cluster. Version matches please make…
CREATE USER in Cassandra CREATE USER alice WITH PASSWORD ‘password_a’ SUPERUSER; CREATE USER bob WITH PASSWORD ‘password_b’ NOSUPERUSER; CREATE USER is equivalent to CREATE ROLE where the LOGIN option is true. So, the following pairs of statements are equivalent: CREATE…
No Load balancers in front of cassandra Cassandra distributes the data across the nodes and most of the cassandra drivers have the algorithm built in to direct requests appropriately . Adding load balancer introduces an additional layer , potentially breaks…
Decrease the default read ahead values in unix/linux systems Most of the modern unix/linux systems use read ahead so that subsequent reads will be cached in to memory . This provides a performance benefit for systems that read data sequentially…
