Fixed issues in Cloudera AI on premises 1.5.5 SP2 CHF1 HF1

Previously, the in‑memory settings for RocksDB were too small for the livelog workload, which led to delays in accessing data on Ceph platform and slowed down all workspace sessions under load.

This issue is now fixed. The block cache is increased to 256 MB, the Memtable is increased to 256 MB and the RocksDB statistics collection is improved. When enabled, RocksDB logs internal counters, the enhanced statistics provide better visibility into cache behavior and background operations.

Previously, various operations on livelog topics used a single global lock that remained held during slow disk operations, causing active sessions to pile up behind one delayed request. Under heavy load, this created significant delays for a large number of topic lookups.

This issue is now fixed. Only requests for the same topic wait on each other. All other lookups continue independently, eliminating performance bottlenecks and improving overall responsiveness.

Previously, the livelog and livelog‑publisher pods used hardcoded operational parameters, preventing users from adjusting performance. In some cases, these defaults caused storage slowdowns that affected all workspace sessions.

This issue is now resolved. Performance and timeout settings are now fully configurable through Kubernetes, and memory tuning is improved to provide smoother, more reliable performance.

Previously, the livelog‑publisher could crash with a concurrent write to websocket error when its WebSocket connection dropped, resulting in temporary loss of container logs.

This issue is now fixed.

Previously, the livelog service deleted topic entries one key at a time, which made topic cleanup slow.

This issue is now fixed. Iterative deletion is replaced with a single bulk delete operation, making topic cleanup significantly faster and more reliable. Related cleanup code was simplified and corrected, resulting in smoother maintenance behavior without changing the external API.

Previously, Jupyter session UIs could freeze permanently when livelog was slow or unresponsive because the system stopped sending status updates and never recovered on its own.

The issue is now fixed. A timeout and safe retry mechanism is added so delayed updates fail quickly and automatically recover. The timeout is set to 30 seconds by default and can be adjusted as needed.

Previously, during the retry of a Cloudera AI workbench upgrade to 1.5.5 SP2 or 1.5.5 SP2 CHF1, or during a fresh upgrade from 1.5.5 SP2 to 1.5.5 SP2 CHF1, the process could fail with an error indicating that the preupgrade workspace PersistentVolume (PV) already exists: persistentvolumes pre-upgrade-workspace-pv-[***WORKBENCH NAME***] already exists.

This occurred when a previous failed upgrade attempt left behind a temporary, undeleted PV, causing subsequent runs to fail immediately.

The issue is now resolved by removing the leftover PV before retrying the upgrade.