Re: Trend Analyser Tool - what should it be able to do?

[Steve Poole <sp...@googlemail.com>]

On Tue, Jan 27, 2009 at 10:32 AM, Christian Glatschke <
christian@glatschke.com> wrote:

> Hi all,
>
> here are some thoughts from my site:
>
> - Which objects have maximum instances across the two dumps?
>
> - What percentage of the heap is occupied by objects of a particular
> package
> across the two dumps ?
> - How have the hot spots changed?
>
> For the user story when we have multiple snapshots of the same system and
> we
> want to analyze:
>
> - how is the heap growing
> - how frequently is gc happening ?
>
> All this metrics can be delivered easily from within a live system by using
> the memory metrics of the jvm.


What metrics are you refering to here how do we get the data?

>
> The only concern might be the cpu overhead, but with a good configuration I
> can imagine this could be done.
> All this data needs to be stored for historical reviews to analize after an
> "Out-of-memory" app crash what caused the memory leak.
>
> This can be real "killer" feature.
>
> Cheers,
>
> Christian Glatschke
>
>
>
>
>
> Sonal Goyal schrieb:
>
>  Hi Steve,
>> I am thinking on the lines of:
>>
>> - Which objects have maximum instances across the two dumps?
>> - What percentage of the heap is occupied by objects of a particular
>> package
>> across the two dumps ?
>> - How have the hot spots changed?
>>
>> For the user story when we have multiple snapshots of the same system and
>> we
>> want to analyze:
>>
>> - how is the heap growing
>> - how frequently is gc happening ?
>> Thanks and Regards,
>> Sonal
>>
>>
>> On Thu, Jan 22, 2009 at 2:11 PM, Steve Poole <spoole167@googlemail.com
>> >wrote:
>>
>>
>>
>>> So what data would you want to compare specifically?
>>>
>>> On Thu, Jan 22, 2009 at 4:44 AM, Sonal Goyal <so...@gmail.com>
>>> wrote:
>>>
>>>
>>>
>>>> Hi,
>>>> I think my main user story behind this tool was:
>>>>
>>>> We release a critical patch onto production and we want to ensure that
>>>>
>>>>
>>> the
>>>
>>>
>>>> system performance is not impacted. If we could compare the pre and post
>>>> patch systems, we would know where things are.
>>>>
>>>> Thanks and Regards,
>>>> Sonal
>>>>
>>>>
>>>> On Wed, Jan 21, 2009 at 8:17 PM, Steve Poole <spoole167@googlemail.com
>>>>
>>>>
>>>>> wrote:
>>>>>        Hi,  more questions for the Expert Group :-)
>>>>>
>>>>> The trend analysis tool concept we've identified has no substance
>>>>>
>>>>>
>>>> behind
>>>
>>>
>>>> it
>>>>
>>>>
>>>>> yet.
>>>>>
>>>>> The reason this tool is on the list is that we identified that there
>>>>>
>>>>>
>>>> were
>>>
>>>
>>>> situations where the monitoring of live systems was not effective  -
>>>>>
>>>>>
>>>> the
>>>
>>>
>>>> main reason cited was that  the live system was changing too much for
>>>>>
>>>>>
>>>> the
>>>
>>>
>>>> monitoring system to cope with . It was felt that the snapshot approach
>>>>> would allow the monitoring system to provide more accurate trending at
>>>>>
>>>>>
>>>> the
>>>>
>>>>
>>>>> cost of it being less frequent.
>>>>>
>>>>> Its easy to say "lets show trends between snapshots" but what does that
>>>>> really mean?
>>>>>
>>>>>
>>>>>
>>>>
>>
>>
>
>