Questions on status json

[ajbeamon]

@harikb

1. For clusters.processes.[instance].disk, there is free_bytes as well as total_bytes (both are given as quantities of RAM, while the key name is ‘disk’). I assume it is indeed RAM information and “disk” label is for symmetry/historic

Free and total bytes are both of the disk, and the comment in our documentation mentioning RAM is incorrect. In addition to these, in the storage and log roles there are some metrics that include space details. These include *_available_bytes (e.g. kvstore_available_bytes), which measures how much space is usable on disk and is in most cases a more interesting number than free_bytes.

@harikb

2. I noticed, with the comments, it isn’t really a valid json. Is there a way for me to submit corrections? pull request on the github repo? For example, a comma is needed after value for key “database_lock_state”.

Yes, if you would like to submit corrections to the website documentation, feel free to add a pull request. You are correct that the website docs are not valid JSON because of the comments, but besides that I think the intent is that they should be valid. There is also a second file which is meant to be kept in sync with the website docs and which I think should be valid (though I haven’t confirmed this). The two files are:

apple/foundationdb/blob/main/documentation/sphinx/source/mr-status-json-schemas.rst.inc

and

apple/foundationdb/blob/main/fdbclient/Schemas.cpp

@harikb

3. My db (“6.3.15”) returns a “logs” key under “clusters”. The document above has only “old_logs”. Is this the way keys/metrics are deprecated? Any way to get a version of this documentation that matches the released FDB?

old_logs here refers to the old generation of transaction logs after a recovery occurs and we recruit new ones and is not meant to imply deprecation. It seems that 6.3 changed what we report here and renamed this field to logs, but that is not reflected in the documentation. I’ll see if I can have that updated.