[ 
https://issues.apache.org/jira/browse/LOG4J2-3672?focusedWorklogId=888476&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-888476
 ]

ASF GitHub Bot logged work on LOG4J2-3672:
------------------------------------------

                Author: ASF GitHub Bot
            Created on: 02/Nov/23 16:27
            Start Date: 02/Nov/23 16:27
    Worklog Time Spent: 10m 
      Work Description: tristantarrant commented on PR #1848:
URL: https://github.com/apache/logging-log4j2/pull/1848#issuecomment-1791067565

   I apologize: I included the wrong layout. This one triggers the call:
   ```xml
    <PatternLayout pattern="%d{dd/MMM/yyyy:HH:mm:ss Z} %-5p %m%throwable%n"/>
    ```
   Removing the `Z` will "fix" it, but then the timestamp will not have the 
Common Log Format (as described here 
https://httpd.apache.org/docs/2.4/logs.html) which is what we need.




Issue Time Tracking
-------------------

    Worklog Id:     (was: 888476)
    Time Spent: 2h 20m  (was: 2h 10m)

> Avoid invoking DateFormatSymbols.getZoneStrings() in FastDateParser
> -------------------------------------------------------------------
>
>                 Key: LOG4J2-3672
>                 URL: https://issues.apache.org/jira/browse/LOG4J2-3672
>             Project: Log4j 2
>          Issue Type: Bug
>            Reporter: Tristan Tarrant
>            Priority: Major
>         Attachments: stacktrace.png
>
>          Time Spent: 2h 20m
>  Remaining Estimate: 0h
>
> {{FastDateParser}} uses {{DateFormatSymbols.getZoneStrings()}} to construct a 
> table of all possible timezone names to be used in parsing date patterns in 
> pattern layouts.
> Unfortunately the above call (and the equivalent call used by the JDK's 
> {{SimpleDateFormat)}} causes initialization and caching of all timezones, 
> resulting in a ~3MB heap overhead on x86_64. The following table summarizes 
> the cost of triggering the caching of all timezones, including the number of 
> instances of some related types and the amount of extra heap required.
>  
> || ||LocalDateTime||LocalDate||ZoneInfo||ZoneOffset||Heap delta||
> |Baseline (no TZ calls)|180|0|0| | |
> |Single timezone|180|0|0|0|298|
> |DateFormatSymbols.getZoneStrings()|57076|32212|602|1455|3760106|
> |TimeZone.getAvailableIds() + TimeZone.getName()|36678|21674|632|1155|3024946|
> |TimeZone.getAvalableIDs()|180|0|632|0|452578|
> By avoiding constructions of such tables, and relying only on 
> {{{}FastDateParser{}}}'s support for RFC-822 and GMT-style timezone names, we 
> can avoid allocating the extra heap.
>  



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

Reply via email to