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"This series introduces some additional metrics (mostly) in a storage_proxy and a database level that are meant to create a better picture of how data flows in the cluster. First of all where possible counters of each category (e.g. total writes in the storage proxy level) are split into the following categories: - operations performed on a local Node - operations performed on remote Nodes aggregated per DC In a storage_proxy level there are the following metrics that have this "split" nature (all on a sending side): - total writes (attempts/errors) - writes performed as a result of a Read Repair logic - total data reads (attempts/completed/errors) - total digest reads (attempts/completed/errors) - total mutations data reads (attempts/completed/errors) In a batchlog_manager: - writes performed as a result of a batchlog replay logic Thereby if for instance somebody wants to get an idea of how many writes the current Node performs due to user requested mutations only he/she has to take a counter of total writes and subtract the writes resulted by Read Repairs and batchlog replays. On a receiving side of a storage_proxy we add the two following counters: - total number of received mutations - total number of forwarded mutations (attempts/errors) In order to get a better picture of what is going on on a local Node we are adding two counters on a database level: - total number of writes - total number of reads Comparing these to total writes/reads in a storage_proxy may give a good idea if there is an excessive access to a local DB for example."