{"id":27255441,"url":"https://github.com/yasuenag/ulviewer","last_synced_at":"2025-09-17T15:33:59.106Z","repository":{"id":80823834,"uuid":"76360547","full_name":"YaSuenag/ulviewer","owner":"YaSuenag","description":"Log viewer for Unified JVM Logging","archived":false,"fork":false,"pushed_at":"2025-03-15T08:22:34.000Z","size":200,"stargazers_count":19,"open_issues_count":0,"forks_count":1,"subscribers_count":3,"default_branch":"master","last_synced_at":"2025-04-11T02:31:08.844Z","etag":null,"topics":["gclog","java9","jvm","jvm-logging","log-parser","ul"],"latest_commit_sha":null,"homepage":null,"language":"Java","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"lgpl-3.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/YaSuenag.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null}},"created_at":"2016-12-13T13:21:04.000Z","updated_at":"2025-03-15T08:22:37.000Z","dependencies_parsed_at":"2024-02-08T14:30:04.862Z","dependency_job_id":"f6165b75-2eb6-48e9-a2fe-f6d0eab4c12a","html_url":"https://github.com/YaSuenag/ulviewer","commit_stats":null,"previous_names":[],"tags_count":12,"template":false,"template_full_name":null,"purl":"pkg:github/YaSuenag/ulviewer","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/YaSuenag%2Fulviewer","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/YaSuenag%2Fulviewer/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/YaSuenag%2Fulviewer/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/YaSuenag%2Fulviewer/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/YaSuenag","download_url":"https://codeload.github.com/YaSuenag/ulviewer/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/YaSuenag%2Fulviewer/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":275620058,"owners_count":25497868,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","status":"online","status_checked_at":"2025-09-17T02:00:09.119Z","response_time":84,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["gclog","java9","jvm","jvm-logging","log-parser","ul"],"created_at":"2025-04-11T02:19:44.136Z","updated_at":"2025-09-17T15:33:59.069Z","avatar_url":"https://github.com/YaSuenag.png","language":"Java","funding_links":[],"categories":[],"sub_categories":[],"readme":"UL Viewer\n![CodeQL](../../workflows/CodeQL/badge.svg)\n===================\n\nUL Viewer is log parser for [JEP 158: Unified JVM Logging](http://openjdk.java.net/jeps/158) and [JEP 271: Unified GC Logging](http://openjdk.java.net/jeps/271).\n\n# How to use\n\n## Start application\n\n### Linux x64\n\n```\n$ cd ulviewer-\u003cversion\u003e-Linux-amd64/bin\n$ ./ulviewer\n```\n\n### Windows x64\n\n* Run `ulviewer.bat`\n* If your machine has WSL (Windows Subsystem for Linux), you can run `ulviewer` directly.\n    * `ulviewer` is shell script.\n\n## Open log(s)\n\nYou can open several logs from [File] -\u003e [Open Log] menu.\n\n## Log parser wizard\n\nAfter selecting logs, Log parser wizard is shown.\n\nYou can choose log decorations for parsing. [Field value] column shows the value of decoration. You can choose decoration format on [Decoration] column. [Decoration] is [ChoiceBox](https://docs.oracle.com/javase/8/javafx/api/javafx/scene/control/ChoiceBox.html), so you can choose Unified JVM Logging official log decorations.  \n\nAfter that, you can push [OK] button.\n\n## Check your logs!\n\nYour logs are shown in main window.\n\n* You can set filters through log decoration. You can choose decoration from [ComboBox](https://docs.oracle.com/javase/8/javafx/api/javafx/scene/control/ComboBox.html), and check on [CheckBox](https://docs.oracle.com/javase/8/javafx/api/javafx/scene/control/CheckBox.html).\n* If you want to search logs with some keywords, you can search it through search window.\n* Copy selected log entry when you press CTRL+C.\n\n### Drawing chart\n\nIf you want to draw chart(s), you have to add tag(s) which indicates time to `-Xlog` option as below:\n\n* `time` (`t`)\n* `utctime` (`utc`)\n* `uptime` (`u`)\n* `timemillis` (`tm`)\n* `uptimemillis` (`um`)\n* `timenanos` (`tn`)\n* `uptimenanos` (`un`)\n\nIn addition, you have to add `tags` (`tg`) to log tags.\n\n#### Java heap chart\n\n* [Chart] -\u003e [Memory] -\u003e [Java heap]\n* You need to open `info` level log (`gc=info`).\n* You can check Java heap memory. This chart shows all STW collection (all major/minor GCs)\n* You can also check specific GC events when you click the plot on the chart.\n\n#### GC pause time chart\n\n* [Chart] -\u003e [Memory] -\u003e [Pause time]\n* You need to open `info` level log (`gc=info`).\n* You can check GC STW time.\n* You can also check specific GC events when you click the plot on the chart.\n\n#### Metaspace chart\n\n* [Chart] -\u003e [Memory] -\u003e [Metaspace]\n* You need to open `info` level log (`gc+metaspace=info`).\n* You can check Metaspace usage and capacity. This chart shows Metaspace GC event.\n\n#### CodeCache chart\n\n* [Chart] -\u003e [Memory] -\u003e [CodeCache]\n* You need to open `debug` level log (`compilation+codecache=debug`).\n* You can check CodeCache usage. This chart stacks CodeCache usage by segments (non-profiled nmethods, profiled nmethods, non-nmethods).\n\n\u003e [!NOTE]\n\u003e UL Viewer would use the value of free memory in `compilation+codecache=debug` - it might be different from actual free size.\n\u003e Both CodeCache Sweeper (~ JDK 19) and GC (for CodeCache: JDK 20~) use free list like CMS GC to manage reclaimed CodeBlob (for nmethod), it does not affect free memory in CodeCache. Free memory in `compilation+codecache=debug` shows unallocated memory only.\n\n#### Class histogram\n\n* [Chart] -\u003e [Memory] -\u003e [Class histogram]\n* You need to open `trace` level log (`gc+classhisto*=trace`).\n* You can check class histogram when Full GC is invoked.\n\n#### VM Operations\n\n* [Chart] -\u003e [VM Operations]\n* You need to open `debug` level log (`vmoperation=debug`).\n* You can check all VM operations.\n\n### Show data table\n\n#### Class loading/unloading\n\n* [Table] -\u003e [Class loading]\n* You need to open `debug` level log for class loading, and need to open `info` level log for class unloading (`class+load=debug,class+unload=info`).\n* You can check class loading / unloading information.\n\n#### Age table\n\n* [Table] -\u003e [Age table]\n* You need to open `trace` level log (`gc+age=trace`).\n* You can check age table when GC is invoked.\n\n# How to build\n\nYou have to use JDK 17 or later.\n\n```\n$ mvn package\n```\n\n# License\n\nThe GNU Lesser General Public License, version 3.0\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fyasuenag%2Fulviewer","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fyasuenag%2Fulviewer","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fyasuenag%2Fulviewer/lists"}