Kirk Pepperdine

Offering Java performance tuning, benchmarking, and workshops.

Unified Logging Tag Sets in OpenJDK

08 Apr 2023 » java, gc, performance

As mentioned in my previous posting on Unified Logging (UL), messages will be associated with both a level and a tag set. The levels are trace, debug, info, warning, and error. Tags can be listed by running java -Xlog:help. The output from JDK 17 is listed here.

add, age, alloc, annotation, arguments, attach, barrier, biasedlocking, blocks, bot, breakpoint, bytecode, cds, census, class, classhisto, cleanup, codecache, compaction, compilation, condy, constantpool, constraints, container, coops, cpu, cset, data, datacreation, dcmd, decoder, defaultmethods, director, dump, dynamic, ergo, event, exceptions, exit, fingerprint, free, freelist, gc, handshake, hashtables, heap, humongous, ihop, iklass, indy, init, inlining, install, interpreter, itables, jfr, jit, jni, jvmci, jvmti, lambda, library, liveness, load, loader, logging, malloc, map, mark, marking, membername, memops, metadata, metaspace, methodcomparator, methodhandles, mirror, mmu, module, monitorinflation, monitormismatch, nestmates, nmethod, nmt, normalize, numa, objecttagging, obsolete, oldobject, oom, oopmap, oops, oopstorage, os, owner, pagesize, parser, patch, path, perf, periodic, phases, plab, placeholders, preorder, preview, promotion, protectiondomain, ptrqueue, purge, record, redefine, ref, refine, region, reloc, remset, resolve, safepoint, sampling, scavenge, sealed, setting, smr, stackbarrier, stackmap, stacktrace, stackwalk, start, startup, startuptime, state, stats, streaming, stringdedup, stringtable, subclass, survivor, suspend, sweep, symboltable, system, table, task, thread, throttle, time, timer, tlab, tracking, unload, unshareable, update, valuebasedclasses, verification, verify, vmmutex, vmoperation, vmthread, vtables, vtablestubs, workgang

Tags Sets

The following table lists tag sets at each logging level available in the product build.

cdscds, classcds, dynamiccds, dynamiccds
cds, heap, mirrorcds, dynamiccds, hashtablescds, heapcds, heap
cds, mirrorcds, heapcds, heapcodecacheclass
cds, unshareablecds, jvmticds, lambdaexceptionsgc
cds, verificationcds, lambdacds, mapgcgc, marking
cds, hashtablescds, mapcds, modulegc, allocgc, task
class, initcds, mirrorcds, dynamicgc, cpugc, verify
class, nestmatescds, relocclass, initgc, ergohandshake
class, sealedcds, resolveclass, loadgc, initjfr
class, unloadcds, vtablesclass, loader, datagc, jvmcijfr, system
continuationsclass, loader, dataclass, nestmatesgc, verifyjfr, system
ergoclass, nestmatesclass, pathifjfr, startup
evt,outclass, pathclass, previewjfrjvmti
gcclass, resolveclass, unloadjfr, startuplogging
gc, agecodecachecodecachejfr, systemmonitorinflation
gc, allocdefaultmethodscompilationjfr, startupos
gc, barrierexceptionsexceptionsjni, resolve 
gc, botgcfinalizerjvmti 
gc, breakpointgc, agegclogging 
gc, ergogc, allocgc, classhistologging, thread 
gc, ergo, csetgc, alloc, regiongc, cpumalloc, free 
gc, ergo, heapgc, alloc, statsgc, ergometaspace 
gc, freelistgc, breakpointgc, heapnmt 
gc, heapgc, directorgc, initos 
gc, heap, coopsgc, ergogc, loados, thread 
gc, heap, numagc, ergo, csetgc, markingpagesize 
gc, livenessgc, ergo, heapgc, metaspaceperf, memops 
gc, markinggc, ergo, ihopgc, mmusafepoint 
gc, metaspacegc, ergo, refinegc, nmethodstringdedup 
gc, metaspace, freelistgc, heapgc, phasesstringtable 
gc, nmethodgc, heap, coopsgc, phasessymboltable 
gc, phasesgc, heap, exitgc, promotion  
gc, plabgc, heap, regiongc, ref  
gc, refgc, humongousgc, region, cds  
gc, refinegc, ihopgc, reloc  
gc, regiongc, initgc, start  
gc, relocgc, jnigc, task  
gc, remset, trackinggc, markinggc, heap  
gc, taskgc, mmugc, ref  
gc, tlabgc, nmethodgc, start  
gc, refgc, periodicgc, task  
handshakegc, phaseshandshake  
interpreter, oopmapgc, plabjfr  
jfrgc, promotionjfr, startup  
jfr, oldobject, samplinggc, refjvmti, table  
jfr, systemgc, refinelibrary  
jvmtigc, refine, statslogging  
logginggc, remsetmembername, table  
membername, tablegc, remset, trackingmetaspace  
membername, tablegc, statsmethodhandles  
metaspacegc, taskmodule, load  
modulegc, task, startmodule, unload  
module, patchgc, tlabmonitorinflation  
monitorinflationgc, verifymonitormismatch  
monitorinflation, ownergc, ergooopstorage, blocks  
nmethod, barrierhandshake, taskoopstorage, blocks, stats  
oopstorage, blocksinterpreter, oopmapos  
oopstorage, refinterpreter, safepointos, cpu  
osjfr, startupos, thread  
os, containerjfr, systempagesize  
os, threadjfr, system, throttleperf, memops  
pagesizejit, inliningredefine, class  
protectiondomainjniredefine, class, constantpool  
redefine, classjni, resolveredefine, class, load  
redefine, class, constantpoolloggingredefine, class, load, exceptions  
redefine, class, dumplogging, threadredefine, class, nestmates  
redefine, class, iklass, addmembername, tableredefine, class, normalize  
redefine, class, iklass, addmetaspaceredefine, class, record  
redefine, class, iklass, purgemethodhandles, indyredefine, class, timer  
redefine, class, normalizemoduleredefine, class, update  
redefine, class, obsoletenmtsafepoint  
redefine, class, obsolete, markoopstorage, blockssafepoint, stats  
redefine, class, obsolete, metadataosstackbarrier  
redefine, class, update, constantpoolos, containerstacktrace  
redefine, class, update, itablesos, threadstringdedup  
redefine, class, update, vtablesos, thread, timerstringdedup, init  
stringdedupperf, datacreationsymboltable  
stringtableperf, memopsthread, table  
symboltableredefine, class, annotationvaluebasedclasses  
thread, suspendredefine, class, breakpointverification  
thread, tableredefine, class, constantpool   
thread, tableredefine, class, interpreter, oopmap   
vmmutexredefine, class, load   
vmthreadredefine, class, methodcomparator   
vtablestubsredefine, class, nmethod   
 redefine, class, stackmap   
 redefine, class, subclass   
 redefine, class, update, constantpool   
 redefine, class, update, vtables   
 stringdedup, phases   
 stringdedup, phases, start   
 stringtable, perf   
 symboltable, perf   
 thread, smr   
 thread, table   

If there are any missing, please shout out in the comments below.