RocksDB functionality: counters and gauges sometimes do not increment/change

[timvaillancourt]

The getServerStatus output for RocksDB was designed to be human-friendly and when numbers in the output get large the precision of the number disappears by applying human-friendly units, example: 10,000,000 will become the string "10M" in the output with no decimal precision.

The problem with this is it cannot be realistically graphed. The number needs to change from 10 million to 11 million for a change to occur in the number, and thus the graphs/metrics we are visualising with this tool.

Example:

rs2:PRIMARY> db.serverStatus().rocksdb.stats[14]
Cumulative writes: 10M writes, 63M keys, 10M batches, 1.0 writes per batch, ingest: 7.50 GB, 0.01 MB/s

This issue is to track a need for a feature in RocksDB or MongoRocks for machine-friendly output values, or at very least numbers with full precision, to resolve this problem.