[PERFORMANCE] Various small enhancements detected thanks to flame graphs - #435
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0.26% CPU resources on formatting a validation message... |
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0.56% running an inefficient algorithm to state which mailboxes have kids, in O(n2). While the percentage is low acting on it with likely improve p99 for |
Arsnael
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May 17, 2021
rouazana
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May 17, 2021
Arsnael
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May 17, 2021
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I confirm the last fixups regarding "computing metadata" do not cost performance.
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This method is responsible of ~2% of total memory allocation as per async-profiler and the builder is the main guilty: Its advanced flags filtering capability, not needed for a copy use case come at a high cost.
By calling `messageMetadata` too frequently we generate too much flag copies that are responsible of over 2% of total memory allocation as per async-profiler.
…wice Field::getBody already perform the operation hence there is no need for it. Async-profiler indicates we spend 0.2% of the CPU needlessly that way... Minor but always good to take!
It was generating it for each requests. Each endpoints needs to initialize its own URI parser. Also the version was parsed for each routes and not just once per request.
String.format was evaluated on each Version and cost 0.26% of total CPU time budget.
…sChildren 0.56% running an inefficient algorithm to state which mailboxes have kids, in O(n2). While the percentage is low acting on it with likely improve p99 for `Mailbox/get` with many mailboxes and is thus worth writing.
Filters are dependent of client request, requiring ObjectMapper reconfiguration as object mapper configuration changes are not thread safe. However ObjectMapper javadoc states the following: ``` Method is typically used when multiple, differently configured mappers are needed. Although configuration is shared, cached serializers and deserializers are NOT shared, which means that the new instance may be re-configured before use; meaning that it behaves the same way as if an instance was constructed from scratch. ``` This sounds like our use case! This conforts to advices of this page: https://github.com/FasterXML/jackson-docs/wiki/Presentation:-Jackson-Performance ``` Reuse heavy-weight objects: ObjectMapper (data-binding) and JsonFactory (streaming API) ```
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Arsnael
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jeantil
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Here we can see a call to
MessageResultImpl::getMessageIdresponsible of0.78%of the total allocated memory... Rationals are that and intermediate (uneeded) on the fly messageMetadata is used, which includes an (innefficient) flag copy.Here is a flame graph capture showing the costs of initializing JMAP routes for each requests.