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.
| Trace | Debug | Info | Warning | Error |
|---|---|---|---|---|
| arguments | attach | arguments | arguments | arguments |
| attach | cds | cds | cds | attach |
| cds | cds, class | cds, dynamic | cds, dynamic | cds |
| cds, heap, mirror | cds, dynamic | cds, hashtables | cds, heap | cds, heap |
| cds, mirror | cds, heap | cds, heap | codecache | class |
| cds, unshareable | cds, jvmti | cds, lambda | exceptions | gc |
| cds, verification | cds, lambda | cds, map | gc | gc, marking |
| cds, hashtables | cds, map | cds, module | gc, alloc | gc, task |
| class, init | cds, mirror | cds, dynamic | gc, cpu | gc, verify |
| class, nestmates | cds, reloc | class, init | gc, ergo | handshake |
| class, sealed | cds, resolve | class, load | gc, init | jfr |
| class, unload | cds, vtables | class, loader, data | gc, jvmci | jfr, system |
| continuations | class, loader, data | class, nestmates | gc, verify | jfr, system |
| ergo | class, nestmates | class, path | if | jfr, startup |
| evt,out | class, path | class, preview | jfr | jvmti |
| gc | class, resolve | class, unload | jfr, startup | logging |
| gc, age | codecache | codecache | jfr, system | monitorinflation |
| gc, alloc | defaultmethods | compilation | jfr, startup | os |
| gc, barrier | exceptions | exceptions | jni, resolve | |
| gc, bot | gc | finalizer | jvmti | |
| gc, breakpoint | gc, age | gc | logging | |
| gc, ergo | gc, alloc | gc, classhisto | logging, thread | |
| gc, ergo, cset | gc, alloc, region | gc, cpu | malloc, free | |
| gc, ergo, heap | gc, alloc, stats | gc, ergo | metaspace | |
| gc, freelist | gc, breakpoint | gc, heap | nmt | |
| gc, heap | gc, director | gc, init | os | |
| gc, heap, coops | gc, ergo | gc, load | os, thread | |
| gc, heap, numa | gc, ergo, cset | gc, marking | pagesize | |
| gc, liveness | gc, ergo, heap | gc, metaspace | perf, memops | |
| gc, marking | gc, ergo, ihop | gc, mmu | safepoint | |
| gc, metaspace | gc, ergo, refine | gc, nmethod | stringdedup | |
| gc, metaspace, freelist | gc, heap | gc, phases | stringtable | |
| gc, nmethod | gc, heap, coops | gc, phases | symboltable | |
| gc, phases | gc, heap, exit | gc, promotion | ||
| gc, plab | gc, heap, region | gc, ref | ||
| gc, ref | gc, humongous | gc, region, cds | ||
| gc, refine | gc, ihop | gc, reloc | ||
| gc, region | gc, init | gc, start | ||
| gc, reloc | gc, jni | gc, task | ||
| gc, remset, tracking | gc, marking | gc, heap | ||
| gc, task | gc, mmu | gc, ref | ||
| gc, tlab | gc, nmethod | gc, start | ||
| gc, ref | gc, periodic | gc, task | ||
| handshake | gc, phases | handshake | ||
| interpreter, oopmap | gc, plab | jfr | ||
| jfr | gc, promotion | jfr, startup | ||
| jfr, oldobject, sampling | gc, ref | jvmti, table | ||
| jfr, system | gc, refine | library | ||
| jvmti | gc, refine, stats | logging | ||
| logging | gc, remset | membername, table | ||
| membername, table | gc, remset, tracking | metaspace | ||
| membername, table | gc, stats | methodhandles | ||
| metaspace | gc, task | module, load | ||
| module | gc, task, start | module, unload | ||
| module, patch | gc, tlab | monitorinflation | ||
| monitorinflation | gc, verify | monitormismatch | ||
| monitorinflation, owner | gc, ergo | oopstorage, blocks | ||
| nmethod, barrier | handshake, task | oopstorage, blocks, stats | ||
| oopstorage, blocks | interpreter, oopmap | os | ||
| oopstorage, ref | interpreter, safepoint | os, cpu | ||
| os | jfr, startup | os, thread | ||
| os, container | jfr, system | pagesize | ||
| os, thread | jfr, system, throttle | perf, memops | ||
| pagesize | jit, inlining | redefine, class | ||
| protectiondomain | jni | redefine, class, constantpool | ||
| redefine, class | jni, resolve | redefine, class, load | ||
| redefine, class, constantpool | logging | redefine, class, load, exceptions | ||
| redefine, class, dump | logging, thread | redefine, class, nestmates | ||
| redefine, class, iklass, add | membername, table | redefine, class, normalize | ||
| redefine, class, iklass, add | metaspace | redefine, class, record | ||
| redefine, class, iklass, purge | methodhandles, indy | redefine, class, timer | ||
| redefine, class, normalize | module | redefine, class, update | ||
| redefine, class, obsolete | nmt | safepoint | ||
| redefine, class, obsolete, mark | oopstorage, blocks | safepoint, stats | ||
| redefine, class, obsolete, metadata | os | stackbarrier | ||
| redefine, class, update, constantpool | os, container | stacktrace | ||
| redefine, class, update, itables | os, thread | stringdedup | ||
| redefine, class, update, vtables | os, thread, timer | stringdedup, init | ||
| safepoint | pagesize | stringtable | ||
| stringdedup | perf, datacreation | symboltable | ||
| stringtable | perf, memops | thread, table | ||
| symboltable | redefine, class, annotation | valuebasedclasses | ||
| thread, suspend | redefine, class, breakpoint | verification | ||
| thread, table | redefine, class, constantpool | |||
| thread, table | redefine, class, interpreter, oopmap | |||
| vmmutex | redefine, class, load | |||
| vmthread | redefine, class, methodcomparator | |||
| vtablestubs | redefine, class, nmethod | |||
| redefine, class, stackmap | ||||
| redefine, class, subclass | ||||
| redefine, class, update, constantpool | ||||
| redefine, class, update, vtables | ||||
| safepoint | ||||
| stackbarrier | ||||
| stackwalk | ||||
| stringdedup | ||||
| stringdedup, phases | ||||
| stringdedup, phases, start | ||||
| stringtable | ||||
| stringtable, perf | ||||
| symboltable | ||||
| symboltable, perf | ||||
| thread | ||||
| thread, smr | ||||
| thread, table | ||||
| verification | ||||
| vmthread |
If there are any missing, please shout out in the comments below.