Chunks chart

You can monitor the state of all chunks in the cluster on the Chunks chart. Chunks can be in the following states:

Healthy

Number and percentage of chunks that have enough active replicas. The normal state of chunks.

Offline

Number and percentage of chunks all replicas of which are offline. Such chunks are completely inaccessible for the cluster and cannot be replicated, read from or written to. All requests to an offline chunk are frozen until a CS that stores that chunk’s replica goes online.

Get offline chunk servers back online as fast as possible, to avoid losing data.

Blocked

Number and percentage of chunks that have fewer active replicas than the set minimum amount. Write requests to a blocked chunk are frozen until it has at least the set minimum amount of replicas. Read requests to blocked chunks are allowed, however, as they still have some active replicas left. Blocked chunks have a higher replication priority than degraded chunks.

Having blocked chunks in the cluster increases the risk of losing data, so postpone any maintenance on working cluster nodes and get offline chunk servers back online as fast as possible.

Degraded

Number and percentage of chunks whose active replicas are few, but not below the set minimum. Such chunks can be read from and written to. However, in the latter case a degraded chunk becomes urgent.

Healthy chunks are highlighted on the scale in green, offline in red, blocked in yellow, and degraded in grey. For example:

The Replication section shows the information about replication activity in the cluster.