Janice is a high-performance file sync tool built to provide superior performance to rsync in large-scale directories with hundreds of thousands of files.
Janice leverages Kotlin Coroutines alongside Java NIO's asynchronous file and networking capabilities to maximize overall system performance.
Check config.json.jsonc for how to configure workspaces.
Check commandline.md for how to launch janice.
If you are using packaged Janice from releases that comes with "run-janice.bat" or "run-janice.sh" script and already included Tencent Kona JDK, just call run-janice and pass command line arguments to it.
Like:
./run-janice.sh --server --config ./config.jsonIf you want to run Janice on your own JDK, please make sure your JDK version is at least 25.
If you want to package Janice yourself, you can do it by simply run python3 scripts/package.py --version {x} , in which {x} is the current version tag defined in build.gradle.kts.
For example, if you see following in build.gradle.kts
val versionMajor = 0
val versionMinor = 0
val versionPatch = 1
val versionTail = "-alpha-evaluation" // like: -devThen your version should be 0.0.1-alpha-evaluation. So you have to run python3 scripts/package.py --version 0.0.1-alpha-evaluation to package Janice yourself.
Janice Protocol is the way Janice processes communicates.
Janice Protocol is specified under folder protocol
You can access protocol version n by reading protocol/{n}.md, in which {n} is the version code like 1.
| Family | First Release Date | Latest | Latest Release Date | Protocol Version(s) |
|---|---|---|---|---|
| 1.0 | 2026-01-14T16:28+08:00 | 1.0.1 | 2026-01-14T18:36+08:00 | 1 |
Janice requires a Java 25 environment.
It is recommended that you use Tencent Kona 25 for running Janice.
But maybe you can simply download from releases, which have Tencent Kona JDK and "run-janice" script included.
Hardware & Software
| Client | Server | |
|---|---|---|
| OS | Windows 11 23H2 22631.6199 | GNU/Linux 6.6.98-40.2.tl4.x86_64 |
| CPU | i9-9900 | EPYC 9754 |
| Memory | DDR4 | |
| Janice | commit 295b3dfb8f316d081458d63691c37461ca3de924 protocol draft | commit 295b3dfb8f316d081458d63691c37461ca3de924 protocol draft |
| rsync | version 3.1.2 protocol version 31 | version 3.2.7 protocol version 31 |
Statistics
| Full Sync | No change | 1 file changed | |
|---|---|---|---|
| Janice | 201 seconds | 3 seconds | 2.7 seconds |
| rsync | 382 seconds | 126 seconds | 119 seconds |
| Performance gain | +90.04% | +4100% | +4307% |
Hardware & Software
| Client | Server | |
|---|---|---|
| OS | Windows 11 23H2 22631.6199 | GNU/Linux 6.6.98-40.2.tl4.x86_64 |
| CPU | i9-9900 | EPYC 9754 |
| Memory | DDR4 | |
| Janice | commit 4da15bcd450e9b8b8dd1a6a5e1cc7a3c9d0589a6 protocol draft | commit 4da15bcd450e9b8b8dd1a6a5e1cc7a3c9d0589a6 protocol draft |
| rsync | version 3.1.2 protocol version 31 | version 3.2.7 protocol version 31 |
Statistics
| Full Sync | No change | 1 file changed | |
|---|---|---|---|
| Janice | 157 seconds | 2.3 seconds | 2.3 seconds |
| rsync | 259 seconds | 66 seconds | 66 seconds |
| Performance gain | +64% | +2769% | +2769% |