On 23/09/2021 11:22, Dumitru Ceara wrote:
> On 9/23/21 12:03 PM, Mark Gray wrote:
>> On 23/09/2021 10:47, Mark Gray wrote:
>>> On 16/09/2021 16:37, Dumitru Ceara wrote:
>>>> Add a new command, 'ovsdb-server/log-db-ops DB TABLE on|off', which
>>>> allows the user to enable/disable transaction logging for specific
>>>> databases and tables.
>>>>
>>>> By default, logging is disabled.  Once enabled, logs are generated
>>>> with level INFO and are also rate limited.
>>>>
>>>> If used with care, this command can be useful in analyzing production
>>>> deployment performance issues, allowing the user to pin point
>>>> bottlenecks without the need to enable wider debug logs, e.g., jsonrpc.
>>>>
>>>> Signed-off-by: Dumitru Ceara <[email protected]>
>>>> ---
>>>> A sample use case is an ovn-kubernetes scaled deployment in which
>>>> we're interesting in reducing time to bring up PODs (represented by
>>>> OVN logical switch ports).  In order to determine exactly where the
>>>> bottleneck is when provisioning PODs (CMS/ovn-nbctl/client
>>>> IDLs/ovsdb-server/ovn-controller/etc) we need timestamps of when
>>>> operations happen at various places in the stack.
>>>>
>>>> Without this patch the only option for tracking when transactions
>>>> happen in the Northbound database is to enable jsonrpc debug logs in
>>>> ovsdb-server.  This generates a rather large amount of data.
>>>>
>>>> Instead, now, users would be able to just enable logging for the
>>>> Logical_Switch_Port table getting more relevant and precise
>>>> information.
>>>>
>>>> V2:
>>>> - rebased (fixed conflicts in NEWS).
>>> Generally ok and I also did a quick test but I have a few comments on
>>> the UI which wouldn't block an ACK and one small comment below in the code:
>>>
>>> * My personal preference would be that the syntax somewhat followed the
>>> vlog/set one that seperates terms by ':'. Also a more memorable name.
>>> For example tlog/set DB:TABLE:on or something like that but feel free to
>>> choose to completely ignore me :) I just find it can sometimes be
>>> difficult to remember syntax so I prefer some consistency.
>>>
>>> * One limititation is that I don't think we can add a log before a table
>>> is created (i.e. to see the first entry). For example, let's say I want
>>> to log the very first creation of a bridge using `ovs-vsctl add-br br0`.
>>> Is there any way around it? I couldn't think of one.
>>>
>>> * Could you make the table and database names case-insensitive. For
>>> example, I can do `ovs-vsctl list open` even though the table name is
>>> actually Open_vSwitch? However, with this I need to specify the actual
>>> table name.
>>>
>>> * There is no way to list the tables that are currently 'on'. Something
>>> like vlog/list.
>>>
>>> * Would it be useful to be able to specify which level to log to?: e.g.
>>>
>>> tlog/set DB:TABLE:info
>>>
>>> * Would it be useful to have a non-verbose mode that only states that an
>>> insert/delete/update happened?
>>>
>>
>> Also, do we need to document this somewhere? I am not sure.
>>
> 
> I'm not sure where though..  I couldn't find documentation (apart from
> occasional mentions in the NEWS file) for the other "ovsdb-server/..."
> appctl commands.
> 

Maybe /ovsdb/ovsdb-server.1 ?

_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev

Reply via email to