On 17/12/12 13:47, Andreas Haupt wrote:
> Hi Maarten,
>
> On Mon, 2012-12-17 at 14:14 +0100, Maarten Litmaath wrote:
>>>> It's a pity that due to the other but, you cannot switch off glite_cream_load_monitor at all :(.
>>>
>>> you can - and in fact that's what we're doing at DESY-ZN. Simply set the
>>> JOB_SUBMISSION_MANAGER_SCRIPT_PATH to /bin/true :
>>>
>>> <parameter name="JOB_SUBMISSION_MANAGER_SCRIPT_PATH" value="/bin/true" />
>>>
>>> Our CREAM runs very stable since then ...
>>
>> The load monitor was invented for a good reason: to protect your CE!
>
> I'm aware of this, and yes - it's actually a nice feature! But the
> chance to make your CE unavailable due to the badly chosen defaults in
> this script is currently *much* higher than running your CE
> "unprotected". This may of course change in future ...
>
>> If its default values are too conservative, you can adjust them and
>> possibly open a ticket for some values to be made more realistic,
>> but beware they need to be safe for small sites with small HW.
>
> Yes, but I currently don't have a "feeling" e.g. what are good values
> for a "standard Tier2 CE" (e.g. maximum number of concurrent gridftp
> connections).
As a point of information, at UKI-LT2-QMUL, we were regularly hitting
the limit of 30. I've just increased it to 60 (which we still hit) on a
dual E5420 machine with 8Gig RAM.
QMUL is a big Tier-2 and currently has 2 cream CEs (partly due to some
transitions - we'll probably have another one soon).
> Maybe we find out some day and then this self-limiting
> feature will be very useful.
>
Chris
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