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--- cloud:technical [2014/03/20 15:21]
rwilson [Userdata scripts]
+++ cloud:technical [2014/03/20 15:24] (current)
rwilson [Known problems & workarounds]
@@ Line 622: / Line 622: @@
 The known problems (14 Jan 2014) are listed below.
-=== dynamictorque 'runaway' ===
-For the last month or so, a 'runaway' behaviour has been noticed in dynamictorque (DT).
-This is shown as a constant desire by DT to increase the number of dynamic cores in use
-even though there appears to be no need for extra cores.
-This graph shows the problem on 8 January, 2014:
-{{cloud:core_usage_20140108.png}}
-Note that after 0900 the number of dynamic cores keeps increasing, even though there are
-no queued jobs and no batch jobs running.
-This may have been noted previously as the reluctance to release unused cores.  It may have been that
-DT was unsuccessfully trying to increase the number of cores because it was asking for N core VMs and
-OpenStack was unable to supply that many cores in one VM.  This state is defined by admin.py showing a
-non-zero number of cores being deleted and at the same time trying to start more cores.  This is the
-state after about 1300 hours in the above graph.
-This behaviour of trying to increase the number of cores when not required and a reluctance to release
-unneeded cores can be seen in the graphs for Jan 2014 12/11/10 and Dec 2013 31/23/19/14/11/9/3.
-This 'runaway' state appears to be triggered by activity in the batch system as days with no activity
-can pass without DT trying to increase the number of cores.
 ===== “cannot find user” errors =====