Replace guava multimap in PCBC with custom impl (Cherry-pick) #1618
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
For a long time PerChannelBookieClient has used guava LinkedListMultiMap to store conflicting V2 completion keys and values. This is problematic though. Completion keys are pooled objects. When a key-value pair is stored in a LinkedListMultiMap, if it is the first value for that key, a collection is created for the values, and added to a top-level map using the key, and then the key and the value are added to the collection. When a second value is added for the same key, the key and value are simply added to the collection. The problem occurs when the first key is removed. PBCB will recycle the key object, but this object is still being used in the multimap in the top-level map. This causes all sorts of fun like NullPointerException and IllegalStateException. Because of this, this patch introduces a very simple multimap implementation that only stores the key one time (in the collection) and uses the hashCode of the key to separate the collections into buckets. It's pretty inefficient, but this code it only hit in the rare case where a client is trying to read or write the same entry from the same ledger more than once at the same time. Author: Ivan Kelly <ivan@ivankelly.net> Reviewers: Enrico Olivelli <eolivelli@gmail.com> This closes apache#1569 from ivankelly/conc-test-flake
sijie
changed the title
eolivelli
approved these changes
Aug 22, 2018
|
there are some conflicts, so I am not very sure if my cherry-pick is right. I would like @ivankelly and @merlimat to have a look to make sure my cherry-pick is correct. |
sijie
pushed a commit
that referenced
this pull request
Aug 22, 2018
Descriptions of the changes in this PR: (cherry-pick #1569) For a long time PerChannelBookieClient has used guava LinkedListMultiMap to store conflicting V2 completion keys and values. This is problematic though. Completion keys are pooled objects. When a key-value pair is stored in a LinkedListMultiMap, if it is the first value for that key, a collection is created for the values, and added to a top-level map using the key, and then the key and the value are added to the collection. When a second value is added for the same key, the key and value are simply added to the collection. The problem occurs when the first key is removed. PBCB will recycle the key object, but this object is still being used in the multimap in the top-level map. This causes all sorts of fun like NullPointerException and IllegalStateException. Because of this, this patch introduces a very simple multimap implementation that only stores the key one time (in the collection) and uses the hashCode of the key to separate the collections into buckets. It's pretty inefficient, but this code it only hit in the rare case where a client is trying to read or write the same entry from the same ledger more than once at the same time. Author: Ivan Kelly <ivanivankelly.net> Reviewers: Enrico Olivelli <eolivelligmail.com> This closes #1569 from ivankelly/conc-test-flake Master Issue: #1569 Author: Ivan Kelly <ivan@ivankelly.net> Reviewers: Ivan Kelly <ivank@apache.org>, Enrico Olivelli <eolivelli@gmail.com> This closes #1618 from sijie/cherry-pick-pcbc
|
This is merged into branch-4.7 as 83d3abe |
reddycharan
pushed a commit
to reddycharan/bookkeeper
that referenced
this pull request
Oct 17, 2018
Descriptions of the changes in this PR: (cherry-pick apache#1569) For a long time PerChannelBookieClient has used guava LinkedListMultiMap to store conflicting V2 completion keys and values. This is problematic though. Completion keys are pooled objects. When a key-value pair is stored in a LinkedListMultiMap, if it is the first value for that key, a collection is created for the values, and added to a top-level map using the key, and then the key and the value are added to the collection. When a second value is added for the same key, the key and value are simply added to the collection. The problem occurs when the first key is removed. PBCB will recycle the key object, but this object is still being used in the multimap in the top-level map. This causes all sorts of fun like NullPointerException and IllegalStateException. Because of this, this patch introduces a very simple multimap implementation that only stores the key one time (in the collection) and uses the hashCode of the key to separate the collections into buckets. It's pretty inefficient, but this code it only hit in the rare case where a client is trying to read or write the same entry from the same ledger more than once at the same time. Author: Ivan Kelly <ivanivankelly.net> Reviewers: Enrico Olivelli <eolivelligmail.com> This closes apache#1569 from ivankelly/conc-test-flake Master Issue: apache#1569 Author: Ivan Kelly <ivan@ivankelly.net> Reviewers: Ivan Kelly <ivank@apache.org>, Enrico Olivelli <eolivelli@gmail.com> This closes apache#1618 from sijie/cherry-pick-pcbc (cherry picked from commit 83d3abe) Signed-off-by: JV Jujjuri <vjujjuri@salesforce.com>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Descriptions of the changes in this PR:
(cherry-pick #1569)
For a long time PerChannelBookieClient has used guava
LinkedListMultiMap to store conflicting V2 completion keys and
values. This is problematic though. Completion keys are pooled
objects. When a key-value pair is stored in a LinkedListMultiMap, if
it is the first value for that key, a collection is created for the
values, and added to a top-level map using the key, and then the key
and the value are added to the collection. When a second value is
added for the same key, the key and value are simply added to the
collection. The problem occurs when the first key is removed. PBCB
will recycle the key object, but this object is still being used in
the multimap in the top-level map. This causes all sorts of fun like
NullPointerException and IllegalStateException.
Because of this, this patch introduces a very simple multimap
implementation that only stores the key one time (in the collection)
and uses the hashCode of the key to separate the collections into
buckets. It's pretty inefficient, but this code it only hit in the
rare case where a client is trying to read or write the same entry
from the same ledger more than once at the same time.
Author: Ivan Kelly ivan@ivankelly.net
Reviewers: Enrico Olivelli eolivelli@gmail.com
This closes #1569 from ivankelly/conc-test-flake
Master Issue: #1569