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JuiceFS Performance Statistics Monitor

JuiceFS exposes a lot of Promethues metrics for monitoring system internal performance. However, when diagnosing performance issues in practice, users may need a more real-time monitoring tool to know what is actually going on within a certain time range. Thus, we provide a command stats to print metrics every second, just like what the Linux command dstat does. The output is like:

stats_watcher

By default, this command will print the following metrics of the JuiceFS process corresponding to the given mount point.

usage

  • cpu: CPU usage of the process
  • mem: physical memory used by the process
  • buf: current buffer size of JuiceFS, limited by mount option --buffer-size

fuse

  • ops/lat: operations processed by FUSE per second, and their average latency (in milliseconds)
  • read/write: read/write bandwidth usage of FUSE

meta

  • ops/lat: metadata operations processed per second, and their average latency (in milliseconds). Please note that, operations returned directly from cache are not counted in, in order to show a more accurate latency of clients actually interacting with metadata engine.

blockcache

  • read/write: read/write bandwidth of client local data cache

object

  • get/put: Get/Put bandwidth between client and object storage

Moreover, users can acquire verbose statistics (like read/write ops and the average latency) by setting --verbosity 1, or customize displayed metrics by changing --schema. For more information, please check juicefs stats -h.