Pulsed Media VM Seedbox Performance And Stability Update

Revolutionized VM Seedbox Performance: Comprehensive Stability and Speed Enhancements Achieved

We are excited to announce a major breakthrough in our new VM seedbox services. After extensive testing, we've successfully eliminated all instances of crashes. This achievement marks a significant improvement in the stability and performance of our VM-based seedboxes. Initially targeting the most problematic nodes, we've implemented systematic changes across all hosts, enhancing stability under high I/O loads. Our automated script streamlines this process, ensuring all participating guests benefit without the need for manual intervention.

Detailed Issue Analysis and Effective Solutions

The root of the stability issues traced back to an old problem with pre-emptive kernels interrupting I/O processes, exacerbated by default Proxmox kernel settings not optimized for heavy I/O loads. This problem became apparent only under extreme conditions, involving high I/O demands across multiple VMs, compounded by shared SSD caching. With targeted I/O setting adjustments, we've eradicated these stability issues.

Some I/O related setting changes later; These issues are gone.

Performance Positively Impacted

Subsequent performance analysis revealed opportunities for further enhancements. Preliminary tests on select nodes have shown promising results, with some instances experiencing up to 3x I/O performance improvements. While these gains vary, they represent a significant step forward in our ongoing quest for excellence in Seedbox services.

Buried in statistics, however, some other related host I/O settings has also been changed which have shown some performance improvement. When these were implemented in a hurry during the worst of energy price crisis schedulers and read aheads were heavily stacked on top of each other. Each scheduler adds latency. These has been fixed now on host level, and slowly rolling out to the guest level too.

Understanding the Initial Oversight

Our initial reliance on synthetic testing, while thorough, failed to replicate the unpredictable nature of real-world usage. Despite positive aggregate performance data, the nuanced complexities of simultaneous VM operations and diverse request patterns eluded our tests. Synthetic testing can only do so much. Real world seedbox usage is chaotic, very chaotic. The natural chaos of real world was missing, ie. fluctuating queue depths, request sizes, all guests heavily active etc etc.

Further, upon inspecting total statistics, everything looked not just fine, but great. Total absolute performance increased by a statistically significant margin, so much infact that it was obvious to human eyes from plain bandwidth utilization graphs. So aggregate data showed performance improvement.

Instability was impossible to test for, it's like a loose electrical connection in your car; Constantly annoying and causing you issues, but you don't know what it is. The moment you take it to a garage, the issue goes away. It was impossible to reproduce, and there was absolutely no data what-so-ever. All you had was instinct/gut-feeling to go with for diagnosis. Therefore, it takes months and months of time to hunt something like this down.

We're now more equipped than ever to deliver an unparalleled VM seedbox experience, characterized by unwavering stability and enhanced performance. This milestone is a testament to our commitment to continuous improvement and customer satisfaction.



Thursday, March 7, 2024

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