0-3 - Unable to access cache path

Other modules reuse the file-based caching mechanism of the Common layer (currently the metadata module), and the file caching mechanism of the Common layer cannot access the directory it specifies.

2022-08-29 00:35:00,189 ERROR [org.apache.dubbo.common.cache.FileCacheStoreFactory:?] - [DUBBO] Cache store path can't be created: , dubbo version: , current host: 10.0.1.1 , error code: 0-3. This may be caused by inaccessible of cache path, go to https://dubbo.apache.org/faq/0/3 to find instructions.
java.nio.file.FileAlreadyExistsException: [Path]
at java.base/sun.nio.fs.WindowsException.translateToIOException(WindowsException.java:87)
at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:103)
at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:108)
at java.base/sun.nio.fs.WindowsFileSystemProvider.createDirectory(WindowsFileSystemProvider.java:521)
at java.base/java.nio.file.Files.createDirectory(Files.java:700)
at java.base/java.nio.file.Files.createAndCheckIsDirectory(Files.java:807)
at java.base/java.nio.file.Files.createDirectories(Files.java:753)
at org.apache.dubbo.common.cache.FileCacheStoreFactory.getInstance(FileCacheStoreFactory.java:90)
...

Possible Reason

  1. Multiple Dubbo processes (or other Java processes) use the same cache file.
  2. Due to the file system permission problem of the directory where the cache file is located, reading and writing fails.

Troubleshooting and resolution steps

  1. According to the actual exception shown below, find the directory that cannot be accessed, and determine its file access permission.
  2. Determine whether other Dubbo instances are accessing this path.
  3. Try to configure Java System Property (Java system properties configured with -D) dubbo.meta.cache.filePath and dubbo.mapping.cache.filePath, specify it as a current user can completely under the control directory.
Last modified January 3, 2023: Merge error code 3-3 to 3-8, 6-4 to 99-0. (#1796) (a687d30ae03)