[wildfly-dev] Design Proposal: Log Viewer

[Stuart Douglas]

I don't think we should be worrying about that. Management operations 
happen under a global lock, and it is already possible to perform 
operations that return a lot of content (e.g. reading the whole resource 
tree).

There would need to be a *lot* of admins and a very under powered server 
to make this a problem, and even then the solution is 'don't do that'.

Stuart

Scott Marlow wrote:
> On 06/11/2014 11:01 AM, James R. Perkins wrote:
>> On 06/10/2014 06:53 PM, Scott Marlow wrote:
>>> Any concern about the number of users viewing the server logs at the
>>> same time and the impact that could have on a system under load?  For
>>> example, if a bunch of users arrive at work around the same time and
>>> they are all curious about how things went last night.  They all could
>>> make a request to show the last 1000 lines of the server.log file (which
>>> could peg the CPU).  You might ask why a large number of users have
>>> access to view the logs but the problem is still worth considering.
>> Actually it's not something I've thought of. Though I suppose this could
>> be an issue with any operation that returns large results.
>
> Would be good to have feedback on how many users are likely to
> concurrently view logs.  I suspect the count will be higher than we
> might expect (depending on which users have access for a particular
> deployment).
>
> One possible solution could be a
> http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/Semaphore.html
> that is configured for the maximum number of users allowed to view logs
> concurrently.  For example, if the number of Semaphore permits is
> configured for five and eighty users are trying to view logs at the same
> time, logs will be returned for five users at a time (until all users
> have received their logs or a timeout occurs).
>
> There are probably other ways to deal with this as well.
>
>>>
>>> On 06/10/2014 07:33 PM, James R. Perkins wrote:
>>>> While there wasn't a huge talk about this at the Brno meeting I know
>>>> Heiko brought it up as part of the extended metrics. It's on some future
>>>> product road maps as well too. I figured I might as well bring it up
>>>> here and get opinions on it.
>>>>
>>>> This design proposal covers how capturing log messages. The "viewer"
>>>> will likely be an operation that returns an object list of log record
>>>> details. The design of how a GUI view would look/work is beyond the
>>>> scope of this proposal.
>>>>
>>>> There is currently an operation to view a log file. This has several
>>>> limitations. The file must be defined as a known file handler. There is
>>>> also no way to filter results, e.g. errors only. If per-deployment
>>>> logging is used, those log messages are not viewable as the files are
>>>> not accessible.
>>>>
>>>> For the list of requirements I'm going to be lazy and just give the link
>>>> the wiki page https://community.jboss.org/wiki/LogViewerDesign.
>>>>
>>>> Implementation:
>>>>
>>>> 1) There will be a new resource on the logging subsystem resource that
>>>> can be enabled or disabled, currently called log-collector. Probably
>>>> some attributes, but I'm not sure what will need to be configurable at
>>>> this point. This will likely act like a handler and be assignable only
>>>> to loggers and not the async-handler.
>>>>
>>>> 2) If a deployment uses per-deployment logging then a separate
>>>> log-collector will need to be added to the deployments log context
>>>>
>>>> 3) Logging profiles will also have their own log-collector.
>>>>
>>>> 4) The messages should be written asynchronously and to a file in some
>>>> kind of formatted structure. The structure will likely be JSON.
>>>>
>>>> 5) An operation to query the messages will need to be create. This
>>>> operation should allow the results to be filtered on various fields as
>>>> well as limit the data set returned and allow for a starting position.
>>>>
>>>> 6) All operations associated with view the log should use RBAC to
>>>> control the access.
>>>>
>>>> 7) Audit logs will eventually need to be viewable and queryable. This
>>>> might be separate from the logging subsystem as it is now, but it will
>>>> need to be done.
>>>>
>>>>
>>>> There are things like how long or how many records should we keep that
>>>> needs to be determined. This could possibly be configurable via
>>>> attributes on the resource.
>>>>
>>>> This is about all I've got at this point. I'd appreciate any feedback.
>>>>
>>> _______________________________________________
>>> wildfly-dev mailing list
>>> wildfly-dev at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/wildfly-dev
>
> _______________________________________________
> wildfly-dev mailing list
> wildfly-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/wildfly-dev