v0.8.9

Features

1. New block-manager compactor (TCompactor). Replaced the block-manager storage scheme's compactor with TCompactor, a Thanos-derived compactor with its own grouper and planner. Blocks can now be grouped by time range and segment before scheduling, so blocks from different segments are never combined (#397).
2. PROMPP_FEATURES=disable_remote_write_http2. Switches every remote-write client to HTTP/1.1 in one place, instead of toggling enable_http2 per destination — useful when a dead pooled HTTP/2 connection keeps failing requests, or a proxy in front of a receiver mishandles HTTP/2 (#472).

Enhancements

1. Remote-write retries are now identifiable on the wire. Every remote-write POST now carries an X-Idempotency-Key (destination + head + segment + message index) that stays stable across retries, and a Retry-Attempt header with the real attempt number instead of a hardcoded 0. The failed-send log now also reports the destination URL, attempt number, duration and message size, and a new connections_total{state="new"|"reused"} counter tracks HTTP connection reuse (#471).

Performance

1. Lower page-cache footprint for block files. Block index/chunk file mmaps are now advised MADV_RANDOM, disabling the kernel's sequential readahead — these files are accessed randomly, so readahead was inflating the container's working set for a long time after restart (#427).

Fixes

1. Potential race condition in the series index's atomic shared pointers. Fixed the ordering of size updates in vector append/erase operations and introduced AtomicSharedPtrControlBlockWithItemCount with acquire/release memory ordering for the entrypoint QEB (#466).