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https://issues.apache.org/jira/browse/HDDS-8765?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Duong updated HDDS-8765:
------------------------
Description:
h2. Problem
Today, OM manages resource (volume, bucket) locks by LockManager, a component
enclosing a lock table as a ConcurrentHashMap to store all active locks. Locks
are dynamically allocated and destroyed in the lock table based on runtime
needs. This means, for every lock allocated, a usage count is kept up to date
to decide when the lock is no longer referenced.
The current performance of LockManager is limited by the cost of maintaining
individual lock liveness, aka, counting how many concurrent usages to a lock
and removing it from the lock table when it's no longer used.
This cost mainly incurs from the need to *synchronize* all the concurrent
access to every lock (or technically, a ConcurrentHashMap section) when:
# When obtaining the lock: create a lock object if it's not existing in the
table and increase the lock usage count.
# When releasing the lock: decrease the usage count and remove the lock when
the usage count is 0.
!Screenshot 2023-06-05 at 4.31.14 PM.png|width=764,height=243!
h2. Experiment
h2. Proposed solution
was:
Today, OM manages resource (volume, bucket) locks by LockManager, a component
enclosing a lock table as a ConcurrentHashMap to store all active locks. Locks
are dynamically allocated and destroyed in the lock table based on runtime
needs.
The current performance of LockManager is limited by the cost of maintaining
individual lock liveness, aka, counting how many concurrent usages to a lock
and removing it from the lock table when it's no longer used.
The cost mainly incurs from the need to *synchronize* all the concurrent access
to every lock (or technically, a ConcurrentHashMap section) when:
# When obtaining the lock: create a lock object if it's not existing in the
table and increase the lock usage count.
# When releasing the lock: decrease the usage count and remove the lock
!Screenshot 2023-06-05 at 4.31.14 PM.png|width=764,height=243!
> OM lock performance improvement
> -------------------------------
>
> Key: HDDS-8765
> URL: https://issues.apache.org/jira/browse/HDDS-8765
> Project: Apache Ozone
> Issue Type: Improvement
> Reporter: Duong
> Priority: Major
> Attachments: Screenshot 2023-06-05 at 4.31.14 PM.png
>
>
> h2. Problem
> Today, OM manages resource (volume, bucket) locks by LockManager, a component
> enclosing a lock table as a ConcurrentHashMap to store all active locks.
> Locks are dynamically allocated and destroyed in the lock table based on
> runtime needs. This means, for every lock allocated, a usage count is kept up
> to date to decide when the lock is no longer referenced.
> The current performance of LockManager is limited by the cost of maintaining
> individual lock liveness, aka, counting how many concurrent usages to a lock
> and removing it from the lock table when it's no longer used.
> This cost mainly incurs from the need to *synchronize* all the concurrent
> access to every lock (or technically, a ConcurrentHashMap section) when:
> # When obtaining the lock: create a lock object if it's not existing in the
> table and increase the lock usage count.
> # When releasing the lock: decrease the usage count and remove the lock when
> the usage count is 0.
> !Screenshot 2023-06-05 at 4.31.14 PM.png|width=764,height=243!
> h2. Experiment
> h2. Proposed solution
>
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