Exception handling

Updated at：2025-11-03

Server exception handling

Exception during multi-step upload to BOS

When the MultiUpload operation is conducted for upload to BOS, FinishUpload is called upon the completion of the final part. Due to the multithreading, the migration of some parts of the same file may not be finished before the migration of the final part is finished. Calling FinishUpload might fail in such cases. The resolution to his problem is as follows: retry 5 times with 20-second intervals, and abort all the previously migrated parts if all 5 retries fail.

Recommendation: If 5 retries still fail, try increasing the blockSize to reduce the total number of parts.

When a server is unavailable, the client detects this upon its first attempt to send a migration request to the server, marks it as unsent, flags the server as unavailable, and refrains from sending further requests to that server. Once the server issue is resolved, you can "touch" the client configuration file client.properties to prompt the client to reload its configuration. Setting up a crontab to periodically touch the client.properties file is recommended.
When the client reaches the limit of fd (socket fd) allocated by the system. Check whether filesPerrequet is too small. If this is confirmed as the cause, it should be increased appropriately. Terminate all servers (or disconnect the client from all servers), wait for most occupied socket fds to be released, and then re-touch the client configuration file.