CA-408552: Improve bootstrom performance by save db ops #6541
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| blocked_by_attach && not allow_attached_vbds | ||
| in | ||
| let* () = | ||
| if blocked_by_attach then |
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This code seems to have been entirely deleted. Or did it get moved elsewhere?
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I do not intent to remove any code, just move the codes to the staring of the function.
Does't it goes to new line number 267?
ocaml/xapi/xapi_vm_lifecycle.ml
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| @@ -777,8 +786,10 @@ let allowable_ops = | |||
| List.filter (fun op -> not (List.mem op ignored_ops)) API.vm_operations__all | |||
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| let update_allowed_operations ~__context ~self = | |||
| let _check = check_operation_error ~__context ~ref:self in | |||
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I'd suggest to avoid naming variables with _ at the beginning: that is reserved for unused values to avoid compiler warnings.
(It is used incorrectly in several places in the code already, but we should avoid propagating that error to new code).
If you want to have 2 functions with similar names you could add a ' at the end, or if you want to completely hide the previous one then you can use the same name again.
events_from_xenopsd thread is critical as it sync up VM status in case of bootstorm, this thread is flood as lots of events comes from xenopsd waiting for process. During processing of the events, VM/VDI/VBD update_allowed_operations will be called to refresh the allowed operations. However, for each ops (start/suspend,etc) for the same object(VM), the object info is always the same no matter what the ops is. Thus, it is not necessary to query the object information over and over again. Disclosure is used to resovle the issue. Query once and the disclosure will just remember the query result. The performance test for starting 500 VM on 4 hosts improve around 10% performance for both XS8 and XS9 Signed-off-by: Lin Liu <[email protected]>
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This is difficult to review on github due to all the moved code.
But the following settings in .config/git/config locally makes reviewing easier, this will showed code that was moved but otherwise unchanged in grey (and ignores indentation changes):
[diff]
algorithm = histogram
colorMoved = dimmed_zebra
colorMovedWS = allow-indentation-change
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It might be easier to review if this was split into multiple commits, e.g. one commit that just introduces the 'fun op' and reindents code, then another that introduces names for things we want to cache ahead of fun op (but doesn't move the code yet) (e.g. 'vdi_is_ha_state_or_redolog'), and then a final commit that just moves the cached values that don't depend on op outside of fun op.
I thought it was a simple update, as I only moved codes to the beginning with low risk. |
events_from_xenopsd thread is critical as it sync up VM status in case of bootstorm, this thread is flood as lots of events comes from xenopsd waiting for process.
During processing of the events, VM/VDI/VBD update_allowed_operations will be called to refresh the allowed operations.
However, for each ops (start/suspend,etc) for the same object(VM), the object info is always the same no matter what the ops is. Thus, it is not necessary to query the object information over and over again.
Disclosure is used to resovle the issue. Query once and the disclosure will just remember the query result.
The performance test for starting 500 VM on 4 hosts improve around 10% performance for both XS8 and XS9