Alexey Serbin created KUDU-3242:
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             Summary: Investigate performance of GetTableSchema when authz 
tokens enabled
                 Key: KUDU-3242
                 URL: https://issues.apache.org/jira/browse/KUDU-3242
             Project: Kudu
          Issue Type: Task
    Affects Versions: 1.13.0, 1.11.1, 1.12.0, 1.11.0, 1.10.1, 1.10.0, 1.14.0
            Reporter: Alexey Serbin


As shown by benchmarks (see {{ConcurrentGetTableSchemaTest.Rpc}} and 
{{ConcurrentGetTableSchemaTest.DirectMethodCall}} test scenarios), processing 
{{GetTableSchema()}} RPC takes much more CPU resources when generating authz 
tokens.  The latter is controlled by the {{\-\-master_support_authz_tokens}} 
flag, which is set to {{true}} by default.

Measuring the maximum achievable rate of requests that kudu-master is able to 
process at a particular node, the difference is in range from 5 to 15 times 
depending on hardware (CPU features, etc.)

Given that the generation of authz tokens is turned on even if authz tokens are 
not used/needed (i.e. no fine-grained authz support via Sentry/Ranger is 
enabled), this might bring unexpected surprises when upgrading from an earlier 
version to 1.11 or later.

As a stop-gap we can disable the generation of authz tokens by default, and it 
should be explicitly enabled with enabling fine-grained authz support.

It's necessary to investigate the issue and find a way to address it in the 
scope of scalability of Kudu clusters.



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