EdenFS exposed Sapling counters

These stats signals are recorded in the Sapling layers. However, they have information that is needed on EdenFS debuggings. Currently we have the following categories of these stats:

A- scmstore.file.fetch.{xxx}.{yyy}.{zzz}:

{xxx} can be aux, indexedlog, lfs which are the place that Sapling fulfill the request

{yyy} can be cache or local which are the place that Sapling fulfill the request.

cache is the hgcache which is the remote server's cache. The objects in cache can be deleted anytime, because it is cache!

local are the files that are modified locally. The objects in local are permanent, and cannot be deleted like cache.

• {zzz} = keys : scmstore.file.fetch.{xxx}.{yyy}.keys
  • The total number of files that are requested in any of those places
• {zzz} = requests : scmstore.file.fetch.{xxx}.{yyy}.requests
  • The total number of requests that are sent to any of those places. Each request has a batch of some keys.
• {zzz} = hits : scmstore.file.fetch.{xxx}.{yyy}.hits
  • The number of files that are fulfilled in any of those places
• {zzz} = misses : scmstore.file.fetch.{xxx}.{yyy}.misses
  • The number of files that are missed in any of those places
• {zzz} = time : scmstore.file.fetch.{xxx}.{yyy}.time
  • The total time that spend to fetch files from any of those places

Note1 : Also, we have scmstore.file.fetch.aux.cache.computed which is the number of computed aux data.

Note2 : Only for indexedlog in addition to file we have tree counters too. It shows the information (keys, requests, hits, misses, and time) for directory requests.

B- scmstore.{xxx}.fetch.edenapi.{yyy}:

These are all the signals that are recorded when Sapling fulfills a {xxx} (file | tree) request from Mononoke.

• {yyy} = hits : scmstore.file.fetch.edenapi.hits
  • The number of files that are fulfilled in Mononoke
• {yyy} = keys : scmstore.file.fetch.edenapi.keys
  • The total number of files that are requested from Mononoke
• {yyy} = requests : scmstore.file.fetch.edenapi.requests
  • The total number of requests that are sent to Mononoke. Each request has a batch of some keys.
• {yyy} = time : scmstore.file.fetch.edenapi.time
  • The total time that spend to fetch files from Mononoke

C- scmstore.{xxx}.fetch.cas.{yyy}:

These are all the signals that are recorded when Sapling fulfills a {xxx} (file | tree) request from CAS.

• {yyy} = hits : scmstore.file.fetch.cas.hits
  • The number of files that are fulfilled in CAS
• {yyy} = keys : scmstore.file.fetch.cas.keys
  • The total number of files that are requested from CAS
• {yyy} = requests : scmstore.file.fetch.cas.requests
  • The total number of requests that are sent to CAS. Each request has a batch of some keys.
• {yyy} = time : scmstore.file.fetch.cas.time
  • The total time that spend to fetch files from CAS

D- eden.edenffi.ffs.{xxx} :

FileteredFS backing store sends a request to Sapling to check the filter for a request object. Sapling collects the following stats which are reported in EdenFS counters:

• {xxx} = lookups : The total number of filter object requests send to Sapling
• {xxx} = lookup_failures : The total number of filter object requests which are failed
• {xxx} = invalid_repo : The total number of filter object requests which has invalid repo
• {xxx} = repo_cache_hits : The total number of filter object requests that don't have to recreate the repo object. It is already in the cache
• {xxx} = repo_cache_misses : The total number of filter object requests that have to recreate the repo object. It is not available in the cache

E- scmstore.{xxx}.fetch.cas.{yyy}.bytes : These are all the signals that are recorded when Sapling fulfills a {xxx} (file | tree) request from CAS.

• {yyy} = zdb : Total number of bytes fetched from the CAS ZippyDb backend
• {yyy} = zgw : Total number of bytes fetched from the CAS ZGW backend
• {yyy} = manifold : Total number of bytes fetched from the CAS Manifold backend
• {yyy} = hedwig : Total number of bytes fetched from the CAS Hedwig backend

F- scmstore.{xxx}.fetch.cas.{yyy}.queries : These are all the signals that are recorded when Sapling fulfills a {xxx} (file | tree) request from CAS.

• {yyy} = zdb : Total number of queries to the CAS ZippyDb backend
• {yyy} = zgw : Total number of queries to the CAS ZGW backend
• {yyy} = manifold : Total number of queries to the CAS Manifold backend
• {yyy} = hedwig : Total number of queries to the CAS Hedwig backend

Note: This commit is a good examples of how to add counters to Sapling.