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Posted to dev@mina.apache.org by Matthew Phillips <ma...@gmail.com> on 2009/07/26 03:25:01 UTC
IoSession throughput counters not working in MINA 2.0M6?
Hello,
I'm using IoSession.getReadBytesThroughput () and
getWrittenBytesThroughput () to output stats from a MINA-based
application, and even under heavy load these are always 0.0. Is there
something I need to enable?
Cheers,
Matthew.
Re: IoSession throughput counters not working in MINA 2.0M6?
Posted by Matthew Phillips <ma...@gmail.com>.
On 27/07/2009, at 9:06 AM, Emmanuel Lecharny wrote:
<snip>
> Matthew Phillips wrote:
>> On 26/07/2009, at 10:19 PM, Emmanuel Lecharny wrote:
>> As an alternative, I could have the filter keep its own stats in an
>> AtomicLong.
> This is what we used in the IoServiceStatistic class. It guarantees
> you that the value is not complete garbage in a concurrent env.
>>
>> I'm sure I'm not telling you anything new here, but it does seem
>> that any reasonable attempt at handling misbehaved clients would
>> need such stats, and handling DOS's (accidental or deliberate) is
>> something nearly every MINA-based app will need to do if it gets
>> deployed in a production environment.
>
> Well, I would say that any decent production system would use
> another system to protect the server against DOS (at least,
> deliberate ones). Now, you are right, it's probably a good idea to
> have a good set of *valid* counters at some point. The only problem
> is to have them implemented correctly ;)
>
> PS: This is an area where MINA can most certainly benefit from some
> large improvement...
Are there any plans to address this before MINA 2.0 is finalised? I'm
on a tight schedule and need to either fix this in MINA, or do it some
other way in the next two weeks or so. If a fix might make its way
into MINA, I might be able to justify doing it "properly".
Assuming I go the "proper" route, it seems like IoSession could use an
equivalent IoSessionStatistics class like IoService has.
Thinking about it more, I don't like the idea of having a stats API
built into IoSession, but it only being enabled if you add the right
filter in the right place, and silently failing if you don't.
One way to fix this would be to have an "IoSession.setStatistics
(IoSessionStatistics newStats)" method which would enable stats
counting (and optionally allow stats from a previous session to be
preserved in the case where a session is re-established, which is
something I could also use). The IoSession would update the stats
itself, but only if enabled: I don't see this adding any measurable
overhead, just a test for statistics == null and a jump in the case
where no stats are needed.
If IoSessionStatistics were an interface/abstract base class, then
this could even be re-implemented to do custom actions on stats changes.
Some API sample code:
public abstract class AbstractIoSession
{
private IoSessionStatistics statistics;
...
public void setStatistics (IoSessionStatistics newStatistics)
{
statistics = newStatistics;
}
/* Actually I'd prefer just "statistics ()", but I think MINA uses
JavaBeans property patterns everywhere else. */
public IoSessionStatistics getStatistics ()
{
return statistics;
}
// Shortcut for the majority who don't care which stats instance is
used
public void setStatisticsEnabled (boolean enabled)
{
if (enabled)
{
if (statistics == null)
statistics = new DefaultIoSessionStatistics ();
} else
{
statistics = null;
}
}
public boolean isStatisticsEnabled ()
{
return statistics != null;
}
// current stats API either removed or implemented as
public final double getReadMessagesThroughput ()
{
if (statistics == null)
throw new IllegalStateException ("Statistics not enabled");
else
return statistics.getReadMessagesThroughput ();
}
...
}
Re: IoSession throughput counters not working in MINA 2.0M6?
Posted by Emmanuel Lecharny <el...@apache.org>.
Matthew Phillips wrote:
> On 26/07/2009, at 10:19 PM, Emmanuel Lecharny wrote:
>
>> Matthew Phillips wrote:
>>> On 26/07/2009, at 6:29 PM, Emmanuel Lecharny wrote:
>>>
>>>> Matthew Phillips wrote:
>>>>> Hello,
>>>>>
>>>>> I'm using IoSession.getReadBytesThroughput () and
>>>>> getWrittenBytesThroughput () to output stats from a MINA-based
>>>>> application, and even under heavy load these are always 0.0. Is
>>>>> there something I need to enable?
>>>> I'm not sure they are still active. We had some issues with
>>>> concurrent updates of those counters.
>>>
>>> I can see that might be tricky with MINA's highly concurrent
>>> architecture. I was planning to implement something like the
>>> counters myself as part of a "bad client" throttling/disconnection
>>> filter. Is it planned to fix the built-in counters before 2.0 final,
>>> or should I proceed to do it myself?
>> IMO, such counters should be thought as a filter, not a base element
>> of the MINA architecture.
>>
>> Having them hard coded make them a bottleneck right now, and
>> introduce some cost that is not generally wanted.
>>
>> So if you think about building them as a filter, I must say that it's
>> probably the best idea. We will probably do that some time in the
>> future anyway...
>
> That would sound reasonable, especially given a filter in the right
> place would (mostly) solve the concurrency problem. But it would be
> problematic for the filter to just call IoSession.updateThroughput (),
> because (a) the counts are long's and therefore not atomically updated
> and (b) the AbstractIoSession.updateThroughput () method updates a
> number of related counters with no sync block, which would mean that
> other threads reading throughput numbers could see garbled results
> (especially if they read a counter half way through it being updated).
>
> As an alternative, I could have the filter keep its own stats in an
> AtomicLong.
This is what we used in the IoServiceStatistic class. It guarantees you
that the value is not complete garbage in a concurrent env.
>
> I'm sure I'm not telling you anything new here, but it does seem that
> any reasonable attempt at handling misbehaved clients would need such
> stats, and handling DOS's (accidental or deliberate) is something
> nearly every MINA-based app will need to do if it gets deployed in a
> production environment.
Well, I would say that any decent production system would use another
system to protect the server against DOS (at least, deliberate ones).
Now, you are right, it's probably a good idea to have a good set of
*valid* counters at some point. The only problem is to have them
implemented correctly ;)
PS: This is an area where MINA can most certainly benefit from some
large improvement...
--
--
cordialement, regards,
Emmanuel Lécharny
www.iktek.com
directory.apache.org
Re: IoSession throughput counters not working in MINA 2.0M6?
Posted by Matthew Phillips <ma...@gmail.com>.
On 26/07/2009, at 10:19 PM, Emmanuel Lecharny wrote:
> Matthew Phillips wrote:
>> On 26/07/2009, at 6:29 PM, Emmanuel Lecharny wrote:
>>
>>> Matthew Phillips wrote:
>>>> Hello,
>>>>
>>>> I'm using IoSession.getReadBytesThroughput () and
>>>> getWrittenBytesThroughput () to output stats from a MINA-based
>>>> application, and even under heavy load these are always 0.0. Is
>>>> there something I need to enable?
>>> I'm not sure they are still active. We had some issues with
>>> concurrent updates of those counters.
>>
>> I can see that might be tricky with MINA's highly concurrent
>> architecture. I was planning to implement something like the
>> counters myself as part of a "bad client" throttling/disconnection
>> filter. Is it planned to fix the built-in counters before 2.0
>> final, or should I proceed to do it myself?
> IMO, such counters should be thought as a filter, not a base element
> of the MINA architecture.
>
> Having them hard coded make them a bottleneck right now, and
> introduce some cost that is not generally wanted.
>
> So if you think about building them as a filter, I must say that
> it's probably the best idea. We will probably do that some time in
> the future anyway...
That would sound reasonable, especially given a filter in the right
place would (mostly) solve the concurrency problem. But it would be
problematic for the filter to just call IoSession.updateThroughput (),
because (a) the counts are long's and therefore not atomically updated
and (b) the AbstractIoSession.updateThroughput () method updates a
number of related counters with no sync block, which would mean that
other threads reading throughput numbers could see garbled results
(especially if they read a counter half way through it being updated).
As an alternative, I could have the filter keep its own stats in an
AtomicLong.
I'm sure I'm not telling you anything new here, but it does seem that
any reasonable attempt at handling misbehaved clients would need such
stats, and handling DOS's (accidental or deliberate) is something
nearly every MINA-based app will need to do if it gets deployed in a
production environment.
Cheers,
Matthew.
Re: IoSession throughput counters not working in MINA 2.0M6?
Posted by Emmanuel Lecharny <el...@apache.org>.
Matthew Phillips wrote:
> On 26/07/2009, at 6:29 PM, Emmanuel Lecharny wrote:
>
>> Matthew Phillips wrote:
>>> Hello,
>>>
>>> I'm using IoSession.getReadBytesThroughput () and
>>> getWrittenBytesThroughput () to output stats from a MINA-based
>>> application, and even under heavy load these are always 0.0. Is
>>> there something I need to enable?
>> I'm not sure they are still active. We had some issues with
>> concurrent updates of those counters.
>
> I can see that might be tricky with MINA's highly concurrent
> architecture. I was planning to implement something like the counters
> myself as part of a "bad client" throttling/disconnection filter. Is
> it planned to fix the built-in counters before 2.0 final, or should I
> proceed to do it myself?
IMO, such counters should be thought as a filter, not a base element of
the MINA architecture.
Having them hard coded make them a bottleneck right now, and introduce
some cost that is not generally wanted.
So if you think about building them as a filter, I must say that it's
probably the best idea. We will probably do that some time in the future
anyway...
--
--
cordialement, regards,
Emmanuel Lécharny
www.iktek.com
directory.apache.org
Re: IoSession throughput counters not working in MINA 2.0M6?
Posted by Matthew Phillips <ma...@gmail.com>.
On 26/07/2009, at 6:29 PM, Emmanuel Lecharny wrote:
> Matthew Phillips wrote:
>> Hello,
>>
>> I'm using IoSession.getReadBytesThroughput () and
>> getWrittenBytesThroughput () to output stats from a MINA-based
>> application, and even under heavy load these are always 0.0. Is
>> there something I need to enable?
> I'm not sure they are still active. We had some issues with
> concurrent updates of those counters.
I can see that might be tricky with MINA's highly concurrent
architecture. I was planning to implement something like the counters
myself as part of a "bad client" throttling/disconnection filter. Is
it planned to fix the built-in counters before 2.0 final, or should I
proceed to do it myself?
Cheers,
Matthew.
Re: IoSession throughput counters not working in MINA 2.0M6?
Posted by Emmanuel Lecharny <el...@apache.org>.
Matthew Phillips wrote:
> Hello,
>
> I'm using IoSession.getReadBytesThroughput () and
> getWrittenBytesThroughput () to output stats from a MINA-based
> application, and even under heavy load these are always 0.0. Is there
> something I need to enable?
I'm not sure they are still active. We had some issues with concurrent
updates of those counters.
--
--
cordialement, regards,
Emmanuel Lécharny
www.iktek.com
directory.apache.org