Exposes a few metrics for Prometheus under /metrics if started with --prometheus.
Example:
# HELP rest_server_blob_read_bytes_total Total number of bytes read from blobs
# TYPE rest_server_blob_read_bytes_total counter
rest_server_blob_read_bytes_total{repo="test",type="data"} 2.13557024e+09
rest_server_blob_read_bytes_total{repo="test",type="index"} 1.198653e+06
rest_server_blob_read_bytes_total{repo="test",type="keys"} 5388
rest_server_blob_read_bytes_total{repo="test",type="locks"} 1975
rest_server_blob_read_bytes_total{repo="test",type="snapshots"} 10018
# HELP rest_server_blob_read_total Total number of blobs read
# TYPE rest_server_blob_read_total counter
rest_server_blob_read_total{repo="test",type="data"} 3985
rest_server_blob_read_total{repo="test",type="index"} 21
rest_server_blob_read_total{repo="test",type="keys"} 12
rest_server_blob_read_total{repo="test",type="locks"} 12
rest_server_blob_read_total{repo="test",type="snapshots"} 32
# HELP rest_server_blob_write_bytes_total Total number of bytes written to blobs
# TYPE rest_server_blob_write_bytes_total counter
rest_server_blob_write_bytes_total{repo="test",type="data"} 1.063726179e+09
rest_server_blob_write_bytes_total{repo="test",type="index"} 395586
rest_server_blob_write_bytes_total{repo="test",type="locks"} 1975
rest_server_blob_write_bytes_total{repo="test",type="snapshots"} 1933
# HELP rest_server_blob_write_total Total number of blobs written
# TYPE rest_server_blob_write_total counter
rest_server_blob_write_total{repo="test",type="data"} 226
rest_server_blob_write_total{repo="test",type="index"} 6
rest_server_blob_write_total{repo="test",type="locks"} 12
rest_server_blob_write_total{repo="test",type="snapshots"} 6
The Linux kernel page cache ALWAYS knows better. Fighting it brings
only worse performance. Usage of fadvise() is wrong 9 out of 10 times.
Removing the whole fs package brings a nice 100% speedup when running
costly prune command. And that is measured on localhost, the improvement
could be much bigger when using network with higher latency.
This brings REST backend up to date with local backend. Repository
format is now identical between them. You can now access REST
repository locally, and vice versa. This is a nice feature!
