GitHub user g0715158 created a discussion: [Bug] Severe performance degradation due to file read hang with single-core max-out
### Search before reporting - [x] I searched in the [issues](https://github.com/apache/pulsar/issues) and found nothing similar. ### Read release policy - [x] I understand that [unsupported versions](https://pulsar.apache.org/contribute/release-policy/#supported-versions) don't get bug fixes. I will attempt to reproduce the issue on a supported version of Pulsar client and Pulsar broker. ### User environment version:3.0.10 jdk 17 os arm ### Issue Description When I split the snapshot and ledgers directories of the bookie from one into four, a problem arises during stress tests with 500KB large messages: file reading gets stuck, resulting in extremely low performance. At this time, IO, network, and overall CPU utilization are all low, but a single CPU core becomes fully saturated. Thread stack analysis shows that the process is blocked in the file reading phase. <!-- Failed to upload "image.png" --> <img width="1490" height="668" alt="Image" src="https://github.com/user-attachments/assets/47672e9c-9cbf-477f-80fd-5e09bf8e3f10"; /> <img width="1692" height="998" alt="Image" src="https://github.com/user-attachments/assets/ccf0aca0-0974-4979-83a1-5f9d2008dfe6"; /> ### Error messages ```text ``` ### Reproducing the issue When I split the snapshot and ledgers directories of the bookie from one into four, a problem arises during stress tests with 500KB large messages: file reading gets stuck, resulting in extremely low performance. At this time, IO, network, and overall CPU utilization are all low, but a single CPU core becomes fully saturated. Thread stack analysis shows that the process is blocked in the file reading phase. ### Additional information _No response_ ### Are you willing to submit a PR? - [ ] I'm willing to submit a PR! GitHub link: https://github.com/apache/pulsar/discussions/25057 ---- This is an automatically sent email for [email protected]. To unsubscribe, please send an email to: [email protected]
