Re: Fwd: Hammer OSD memory increase when add new machine

Re: Fwd: Hammer OSD memory increase when add new machine

[zphj1987]

[-- Attachment #1.1: Type: text/plain, Size: 2700 bytes --]

I  remember CERN had a test ceph cluster 30PB  and the osd use more memery
 than usual   ,and thay tune osdmap_epochs ,if it is the osdmap make it use
more memery,ithink  you may have a test use less osdmap_epochs to see if
have some change

default mon_min_osdmap_epochs is 500


zphj1987

2016-11-08 22:08 GMT+08:00 Sage Weil <sage-BnTBU8nroG7k1uMJSBkQmQ@public.gmane.org>:

> > ---------- Forwarded message ----------
> > From: Dong Wu <archer.wudong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > Date: 2016-10-27 18:50 GMT+08:00
> > Subject: Re: [ceph-users] Hammer OSD memory increase when add new machine
> > To: huang jun <hjwsm1989-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > 抄送： ceph-users <ceph-users-idqoXFIVOFJgJs9I8MT0rw@public.gmane.org>
> >
> >
> > 2016-10-27 17:50 GMT+08:00 huang jun <hjwsm1989-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>:
> > > how do you add the new machine ?
> > > does it first added to default ruleset and then you add the new rule
> > > for this group?
> > > do you have data pool use the default rule, does these pool contain
> data?
> >
> > we dont use default ruleset, when we add new group machine,
> > crush_location auto generate root and chassis, then we add a new rule
> > for this group.
> >
> >
> > > 2016-10-27 17:34 GMT+08:00 Dong Wu <archer.wudong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>:
> > >> Hi all,
> > >>
> > >> We have a ceph cluster only use rbd. The cluster contains several
> > >> group machines, each group contains several machines, then each
> > >> machine has 12 SSDs, each ssd as an OSD (journal and data together).
> > >> eg:
> > >> group1: machine1~machine12
> > >> group2: machine13~machine24
> > >> ......
> > >> each group is separated with other group, which means each group has
> > >> separated pools.
> > >>
> > >> we use Hammer(0.94.6) compiled with jemalloc(4.2).
> > >>
> > >> We have found that when we add a new group machine, the other group
> > >> machine's memory increase 5% more or less (OSDs usage).
> > >>
> > >> each group's data is separated with others, so backfill only in group,
> > >> not across.
> > >> Why add a group of machine cause others memory increase? Is this
> reasonable?
>
> It could be cached OSDmaps (they get slightly larger when you add OSDs)
> but it's hard to say.  It seems more likely that the pools and crush rules
> aren't configured right and you're adding OSDs to the wrong group.
>
> If you look at the 'ceph daemon osd.NNN perf dump' output you can see,
> among other things, how many PGs are on the OSD.  Can you capture the
> output before and after the change (and 5% memory footprint increase)?
>
> sage
>

[-- Attachment #1.2: Type: text/html, Size: 4082 bytes --]

[-- Attachment #2: Type: text/plain, Size: 178 bytes --]

_______________________________________________
ceph-users mailing list
ceph-users-idqoXFIVOFJgJs9I8MT0rw@public.gmane.org
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com

Re: Fwd: [ceph-users] Hammer OSD memory increase when add new machine

[Dong Wu]

Thanks, though CERN 30PB cluster test, the osdmap caches causes memory
increase, I'll test how these configs( osd_map_cache_size,
osd_map_max_advance, etc.) influence the memory usage.

2016-11-08 22:48 GMT+08:00 zphj1987 <zphj1987@gmail.com>:
> I  remember CERN had a test ceph cluster 30PB  and the osd use more memery
> than usual   ,and thay tune osdmap_epochs ,if it is the osdmap make it use
> more memery,ithink  you may have a test use less osdmap_epochs to see if
> have some change
>
> default mon_min_osdmap_epochs is 500
>
>
> zphj1987
>
> 2016-11-08 22:08 GMT+08:00 Sage Weil <sage@newdream.net>:
>>
>> > ---------- Forwarded message ----------
>> > From: Dong Wu <archer.wudong@gmail.com>
>> > Date: 2016-10-27 18:50 GMT+08:00
>> > Subject: Re: [ceph-users] Hammer OSD memory increase when add new
>> > machine
>> > To: huang jun <hjwsm1989@gmail.com>
>> > 抄送： ceph-users <ceph-users@lists.ceph.com>
>> >
>> >
>> > 2016-10-27 17:50 GMT+08:00 huang jun <hjwsm1989@gmail.com>:
>> > > how do you add the new machine ?
>> > > does it first added to default ruleset and then you add the new rule
>> > > for this group?
>> > > do you have data pool use the default rule, does these pool contain
>> > > data?
>> >
>> > we dont use default ruleset, when we add new group machine,
>> > crush_location auto generate root and chassis, then we add a new rule
>> > for this group.
>> >
>> >
>> > > 2016-10-27 17:34 GMT+08:00 Dong Wu <archer.wudong@gmail.com>:
>> > >> Hi all,
>> > >>
>> > >> We have a ceph cluster only use rbd. The cluster contains several
>> > >> group machines, each group contains several machines, then each
>> > >> machine has 12 SSDs, each ssd as an OSD (journal and data together).
>> > >> eg:
>> > >> group1: machine1~machine12
>> > >> group2: machine13~machine24
>> > >> ......
>> > >> each group is separated with other group, which means each group has
>> > >> separated pools.
>> > >>
>> > >> we use Hammer(0.94.6) compiled with jemalloc(4.2).
>> > >>
>> > >> We have found that when we add a new group machine, the other group
>> > >> machine's memory increase 5% more or less (OSDs usage).
>> > >>
>> > >> each group's data is separated with others, so backfill only in
>> > >> group,
>> > >> not across.
>> > >> Why add a group of machine cause others memory increase? Is this
>> > >> reasonable?
>>
>> It could be cached OSDmaps (they get slightly larger when you add OSDs)
>> but it's hard to say.  It seems more likely that the pools and crush rules
>> aren't configured right and you're adding OSDs to the wrong group.
>>
>> If you look at the 'ceph daemon osd.NNN perf dump' output you can see,
>> among other things, how many PGs are on the OSD.  Can you capture the
>> output before and after the change (and 5% memory footprint increase)?
>>
>> sage
>
>

Re: Fwd: [ceph-users] Hammer OSD memory increase when add new machine

[Sage Weil]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 2019 bytes --]

> ---------- Forwarded message ----------
> From: Dong Wu <archer.wudong@gmail.com>
> Date: 2016-10-27 18:50 GMT+08:00
> Subject: Re: [ceph-users] Hammer OSD memory increase when add new machine
> To: huang jun <hjwsm1989@gmail.com>
> 抄送： ceph-users <ceph-users@lists.ceph.com>
> 
> 
> 2016-10-27 17:50 GMT+08:00 huang jun <hjwsm1989@gmail.com>:
> > how do you add the new machine ?
> > does it first added to default ruleset and then you add the new rule
> > for this group?
> > do you have data pool use the default rule, does these pool contain data?
> 
> we dont use default ruleset, when we add new group machine,
> crush_location auto generate root and chassis, then we add a new rule
> for this group.
> 
> 
> > 2016-10-27 17:34 GMT+08:00 Dong Wu <archer.wudong@gmail.com>:
> >> Hi all,
> >>
> >> We have a ceph cluster only use rbd. The cluster contains several
> >> group machines, each group contains several machines, then each
> >> machine has 12 SSDs, each ssd as an OSD (journal and data together).
> >> eg:
> >> group1: machine1~machine12
> >> group2: machine13~machine24
> >> ......
> >> each group is separated with other group, which means each group has
> >> separated pools.
> >>
> >> we use Hammer(0.94.6) compiled with jemalloc(4.2).
> >>
> >> We have found that when we add a new group machine, the other group
> >> machine's memory increase 5% more or less (OSDs usage).
> >>
> >> each group's data is separated with others, so backfill only in group,
> >> not across.
> >> Why add a group of machine cause others memory increase? Is this reasonable?

It could be cached OSDmaps (they get slightly larger when you add OSDs) 
but it's hard to say.  It seems more likely that the pools and crush rules 
aren't configured right and you're adding OSDs to the wrong group.

If you look at the 'ceph daemon osd.NNN perf dump' output you can see, 
among other things, how many PGs are on the OSD.  Can you capture the 
output before and after the change (and 5% memory footprint increase)?

sage

Fwd: [ceph-users] Hammer OSD memory increase when add new machine

[Dong Wu]

any sugesstions?

Thanks.


---------- Forwarded message ----------
From: Dong Wu <archer.wudong@gmail.com>
Date: 2016-10-27 18:50 GMT+08:00
Subject: Re: [ceph-users] Hammer OSD memory increase when add new machine
To: huang jun <hjwsm1989@gmail.com>
抄送： ceph-users <ceph-users@lists.ceph.com>


2016-10-27 17:50 GMT+08:00 huang jun <hjwsm1989@gmail.com>:
> how do you add the new machine ?
> does it first added to default ruleset and then you add the new rule
> for this group?
> do you have data pool use the default rule, does these pool contain data?

we dont use default ruleset, when we add new group machine,
crush_location auto generate root and chassis, then we add a new rule
for this group.


> 2016-10-27 17:34 GMT+08:00 Dong Wu <archer.wudong@gmail.com>:
>> Hi all,
>>
>> We have a ceph cluster only use rbd. The cluster contains several
>> group machines, each group contains several machines, then each
>> machine has 12 SSDs, each ssd as an OSD (journal and data together).
>> eg:
>> group1: machine1~machine12
>> group2: machine13~machine24
>> ......
>> each group is separated with other group, which means each group has
>> separated pools.
>>
>> we use Hammer(0.94.6) compiled with jemalloc(4.2).
>>
>> We have found that when we add a new group machine, the other group
>> machine's memory increase 5% more or less (OSDs usage).
>>
>> each group's data is separated with others, so backfill only in group,
>> not across.
>> Why add a group of machine cause others memory increase? Is this reasonable?
>>
>> _______________________________________________
>> ceph-users mailing list
>> ceph-users@lists.ceph.com
>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>
>
>
>
> --
> Thank you!
> HuangJun