Re: [pve-devel] [PATCH manager v3 1/2] api: ceph: add applications of each pool to the lspools endpoint

[Stefan Sterz <s.sterz@proxmox.com>]

On 10/20/22 14:55, Thomas Lamprecht wrote:
> Am 20/10/2022 um 09:17 schrieb Stefan Sterz:
>> since ceph luminous (ceph 12) pools need to be associated with at
>> least one applicaton. expose this information here too so that clients
>> of this endpoint can use it
>>
>> Signed-off-by: Stefan Sterz <s.sterz@proxmox.com>
>> ---
>> v3: add an api viewer entry for the applications object
>>
>> thanks @ alwin antreich for pointing out that pools have applications!
>>
>>  PVE/API2/Ceph/Pools.pm | 11 +++++++++++
>>  1 file changed, 11 insertions(+)
>>
>> diff --git a/PVE/API2/Ceph/Pools.pm b/PVE/API2/Ceph/Pools.pm
>> index 6c05250e..f5984c2c 100644
>> --- a/PVE/API2/Ceph/Pools.pm
>> +++ b/PVE/API2/Ceph/Pools.pm
>> @@ -125,6 +125,11 @@ __PACKAGE__->register_method ({
>>  		    title => 'Autoscale Status',
>>  		    optional => 1,
>>  		},
>> +		applications => {
>> +		    type => 'object',
>> +		    title => 'Associated Applications',
>> +		    optional => 1,
>> +		},
>>  	    },
>>  	},
>>  	links => [ { rel => 'child', href => "{pool_name}" } ],
>> @@ -167,6 +172,8 @@ __PACKAGE__->register_method ({
>>  	# pg_autoscaler module is not enabled in Nautilus
>>  	my $autoscale = eval { $get_autoscale_status->($rados) };
>>  
>> +	my $apps = eval { $rados->mon_command({ prefix => 'osd pool application get' }) };
> 
> out of interest: how expensive is this, did you check the overhead?
> 

do you want a specific metric? in my (admittedly small) test setup
(three vm cluster with 4 cores and 4Gib RAM) it is barely noticeable.
the api call takes between 18 and 25ms in both cases for me.

>> +
>>  	foreach my $e (@{$res->{pools}}) {
>>  	    my $d = {};
>>  	    foreach my $attr (@$attr_list) {
>> @@ -191,6 +198,10 @@ __PACKAGE__->register_method ({
>>  		$d->{percent_used} = $s->{percent_used};
>>  	    }
>>  
>> +	    if ($apps) {
>> +		$d->{applications} = $apps->{$d->{pool_name}} if $apps->{$d->{pool_name}};
> 
> no nested hashes-in-hashes, pull out $d->{pool_name} earlier and then make it an one
> liner:
> 
> $d->{applications} = $apps->{$pool} if defined($apps->{$pool});
> 

noted, ill avoid that in the future.

>> +	    }
>> +
>>  	    # Cephs numerical pool types are barely documented. Found the following in the Ceph
>>  	    # codebase: https://github.com/ceph/ceph/blob/ff144995a849407c258bcb763daa3e03cfce5059/src/osd/osd_types.h#L1221-L1233
>>  	    if ($e->{type} == 1) {
>