Question:
A pretty weird situation I observed while executing a meta-chain, here's the metachain design :
.......... Main Chain
................|
--------------------------------
....|................|.................|
Chain 1........Chain2........Chain3
... |................|.................|
<----- other processes------->
Now, when the main chain executes, though the design shows it as parallel, Chain 2 does not start until Chain 1 completes succesfully and likewise with Chain 3 & Chain 2...
Any idea why ? or a way around this so that these three chains can be triggered off parallelly ? .. The link to the Chains are not success-dependent but are 'always' links.. pretty black in colour!
Has anyone seen this behaviour ? Any suggestions for getting them in parallel ?
Answer:
Number of background processes?
Leandro
Answer:
No problem on that end... I checked that up with the BASIS chaps.. no problem with BG processes.. no Locks...
The chain triggering simply won't start parallely, it just starts one after the other from the right side !
_________________
- Nike
Answer:
I seem to remember that each process chain active process runs in a dialog - therefore if you run parallel you will be using 2 dialogs. Parallel data loads (options 2 and 3 in InfoPackage process tab) also use dialogs. Perhaps you have lack of dialogs.
Ken
Answer:
Lemme check that up.... a funny thing is, a colleague of mine put in another process chain where he was triggering six data loads... that starts in parallel !
Same system - no changes, i tried again, no luck, still runs in sequence !
Answer:
INSIGHTS ON PC & BG PROCESSES
Make sure that there are enough background processes in the system.
If the minimum requirement cannot be met, SAP recommends that you adjust the chain to reduce the number of parallel subchains.
Minimum (with this setting, the chain runs more or less serially):
Number of parallel subchains at the widest part of the chains + 1
Subchains that start additional subchains must be exploded for the calculation.
Optimal (higher similarity):
Number of parallel processes at the widest part of the chain + 1.
Every subchain counts here in this formula with the number of parallel processes at its widest point.
Example: Following chain (observed in the detail view!):
---Load process-Load process--AND
| |
Trigger--|--Load process--AND----------Load process
| |
---Subchain---AND------------
# processes: 1P 2P+1U 3P 2P
In this case, you require at least 1U + 1 = 2 batch processes.
The optimal setting would assume the subchain has 3 load processes at its widest point:2 (load processes) + 3 (load processes of the subchain) + 1 = 6 load processes.
CAUTION:
Note that a higher degree of parallel processing and therefore more batch processes only make sense if the system has sufficient capacity (CPUs). You must use approximately one CPU per batch task.
Hope it Helps
_________________
Chetan
@ CP...