riakkv_1h_kv_put_mean_latency.md 2.1 KB

Understand the alert

The riakkv_1h_kv_put_mean_latency alert calculates the average time (in milliseconds) between the reception of client PUT requests and the subsequent responses to the clients over the last hour in a Riak KV database. If you receive this alert, it means that your Riak KV database is experiencing higher than normal latency in processing PUT requests.

What is Riak KV?

Riak KV is a distributed NoSQL key-value data store designed to provide high availability, fault tolerance, operational simplicity, and scalability. The primary access method is through PUT, GET, DELETE, and LIST operations on keys.

What does PUT latency mean?

PUT latency refers to the time it takes for the system to process a PUT request - from the moment the server receives the request until it sends a response back to the client. High PUT latency can impact the performance and responsiveness of applications relying on the Riak KV database.

Troubleshoot the alert

  • Check the Riak KV cluster health

Use the riak-admin cluster status command to get an overview of the Riak KV cluster's health. Make sure there are no unreachable or down nodes in the cluster.

  • Verify the Riak KV node performance

Use the riak-admin status command to display various statistics of the Riak KV nodes. Pay attention to the node_put_fsm_time_mean and node_put_fsm_time_95 metrics, as they are related to PUT latency.

  • Inspect network conditions

Use networking tools (e.g., ping, traceroute, mtr, iftop) to check for potential network latency issues between clients and the Riak KV servers.

  • Evaluate the workload

If the client application is heavily write-intensive, consider optimizing it to reduce the number of write operations or increase the capacity of the Riak KV cluster to handle the load.

  • Review Riak KV logs

Examine the Riak KV logs (/var/log/riak/riak_kv.log by default) for any error messages or unusual patterns that might be related to the increased PUT latency.

Useful resources

  1. Riak KV Official Documentation