Jiao Zhang created KAFKA-9685: --------------------------------- Summary: Solve Set concatenation perf issue in AclAuthorizer Key: KAFKA-9685 URL: https://issues.apache.org/jira/browse/KAFKA-9685 Project: Kafka Issue Type: Improvement Components: security Affects Versions: 1.1.0 Reporter: Jiao Zhang
In version 1.1, https://github.com/apache/kafka/blob/71b1e19fc60b5e1f9bba33025737ec2b7fb1c2aa/core/src/main/scala/kafka/security/auth/SimpleAclAuthorizer.scala#L110 the logic for checking acls is preparing a merged acl Set with 'acls = getAcls(new Resource(resource.resourceType, Resource.WildCardResource)) ++ getAcls(resource);' and then pass it as aclMatch's parameter. We found scala's Set '++' operation is very slow for example in the case that the Set on right hand of '++' has more than 100 entries. And the bad performance of '++' is due to iterating every entry of the Set on right hand of '++' in which the calculation of HashCode seems heavy. The performance of 'authorize' is important as each request delivered to broker goes through the logic, that's the reason we can't leave it as-is although the change for this proposal seems trivial. Here is the approach. We propose to solve this issue by introducing a new class 'AclSets' which takes multiple Sets as parameters and do 'find' against them one by one. ``` class AclSets(sets: Set[Acl]*) { def find(p: Acl => Boolean): Option[Acl] = sets.flatMap(_.find(p)).headOption def isEmpty: Boolean = !sets.exists(_.nonEmpty) } ``` This approach avoids the Set '++' operation, and thus outperforms a lot compared to old '++' logic. The benchmark result(we did the test with kafka version 1.1) shows notable difference under the condition: 1. set on left consists of 60 entries 2. set of right consists of 30 entries 3. search for absent entry (so that all entries are iterated) Benchmark Results is as following. Mode Cnt Score Error Units ScalaSetConcatination.Set thrpt 3 281.974 ± 140.029 ops/ms ScalaSetConcatination.AclSets thrpt 3 887.426 ± 40.261 ops/ms As the upstream also use the similar ++ operation, https://github.com/apache/kafka/blob/trunk/core/src/main/scala/kafka/security/authorizer/AclAuthorizer.scala#L360 we think it's necessary to fix this issue. -- This message was sent by Atlassian Jira (v8.3.4#803005)