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https://issues.apache.org/jira/browse/IGNITE-27438?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Alexey Scherbakov updated IGNITE-27438:
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Description:
Currently each expicit tx operation is executed on a primary replica and adds
an RTT to transaction latency for each operation.
This can be optimized by buffering "blind" writes (unconditinal puts) on a tx
coordinator until commit.
Similar optimization exists in AI3.
This gives several benefits:
1. Only read operation causes network round trips.
2. Subsequent reads can be served locally. For example
{code:java}
int val = table.get(tx, key);
table.put(tx, key, val + 1);
{code}
will produce only one RT.
3. Single partition transactions can be committed in one phase, greatly
reducing latency.
There are also drawbacks:
1. We need additionaly memory to buffer tuples. The optimization is applicable
to only small transactions.
2. Mixed KV + SQL case stops working. Only KV transactions are affected.
was:
Currently each expicit tx operations is executed on a primary replica.
This causes additional RTTs and add latency to a transaction.
This can be optimized by buffering "blind" writes (unconditinal puts) on a tx
coordinator until commit.
Similar optimization exists in AI3.
This gives several benefits:
1. Only read operations cause network round trips.
2. Subsequent reads can be served locally. For example
{code:java}
int val = table.get(tx, key);
table.put(tx, key, val + 1);
{code}
will produce only one RT.
3. Single partition transactions can be committed in one phase, greatly
reducing latency.
There are also drawbacks:
1. We need additionaly memory to buffer tuples. So, the optimization is
applicable to only small transactions.
2. Mixed KV + SQL case stops working.
> Delay writes until expicit transaction commit
> ---------------------------------------------
>
> Key: IGNITE-27438
> URL: https://issues.apache.org/jira/browse/IGNITE-27438
> Project: Ignite
> Issue Type: Improvement
> Affects Versions: 3.3
> Reporter: Alexey Scherbakov
> Priority: Major
> Labels: ignite-3
>
> Currently each expicit tx operation is executed on a primary replica and adds
> an RTT to transaction latency for each operation.
> This can be optimized by buffering "blind" writes (unconditinal puts) on a tx
> coordinator until commit.
> Similar optimization exists in AI3.
> This gives several benefits:
> 1. Only read operation causes network round trips.
> 2. Subsequent reads can be served locally. For example
> {code:java}
> int val = table.get(tx, key);
> table.put(tx, key, val + 1);
> {code}
> will produce only one RT.
> 3. Single partition transactions can be committed in one phase, greatly
> reducing latency.
> There are also drawbacks:
> 1. We need additionaly memory to buffer tuples. The optimization is
> applicable to only small transactions.
> 2. Mixed KV + SQL case stops working. Only KV transactions are affected.
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