As reported in LOG4J2-3672 <https://issues.apache.org/jira/browse//LOG4J2-3672>, `FastDateParser`[1] contains `DateFormatSymbols#getZoneStrings()`, which causes initialization and caching of all time zones, resulting in a ~3MB heap overhead on x86_64. The reporter also provided the PR #1848 <https://github.com/apache/logging-log4j2/pull/1848>, though it needs several assumptions to hold to be effective.
Curious: *In the context of logging, does `FastDateParser` need to be fast while parsing?* We certainly need to *"format"* the instant fast. Though do we really need to *"parse"* it fast too? [1] FDP was borrowed from Apache Commons Lang in 2015. I have checked the most recent version <https://github.com/apache/commons-lang/blob/5b5656a8b403fd91284b0d2acc893dac7ebd5c29/src/main/java/org/apache/commons/lang3/time/FastDateParser.java#L932>, they still use `getZoneStrings()`.