perf: add concurrent keyspace mode (--concurrent flag) - #50
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adds an experimental mode that uses DashMap for lock-free concurrent access, bypassing the sharded channel architecture for GET/SET commands. benchmark results on 8-core VM: - SET: +13% throughput (1,010k → 1,142k ops/sec) - GET: +11% throughput (1,115k → 1,241k ops/sec) the improvement comes from eliminating the per-request channel overhead (mpsc send + oneshot reply) that exists in the sharded architecture. new files: - concurrent.rs: DashMap-backed ConcurrentKeyspace - concurrent_handler.rs: connection handler for concurrent mode usage: ember-server --concurrent
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* perf: add concurrent keyspace mode (--concurrent flag) adds an experimental mode that uses DashMap for lock-free concurrent access, bypassing the sharded channel architecture for GET/SET commands. benchmark results on 8-core VM: - SET: +13% throughput (1,010k → 1,142k ops/sec) - GET: +11% throughput (1,115k → 1,241k ops/sec) the improvement comes from eliminating the per-request channel overhead (mpsc send + oneshot reply) that exists in the sharded architecture. new files: - concurrent.rs: DashMap-backed ConcurrentKeyspace - concurrent_handler.rs: connection handler for concurrent mode usage: ember-server --concurrent * chore: fmt and clippy fixes
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summary
adds an experimental
--concurrentflag that uses DashMap for lock-free concurrent access, bypassing the sharded channel architecture for GET/SET commands.benchmark results
IMPORTANT: previous benchmarks used single-threaded redis-benchmark, which bottlenecked the client. With
--threads 8, the true scaling behavior is revealed:concurrent mode is:
tested on GCP c2-standard-8 (8 vCPU Intel Xeon @ 3.10GHz)
what's new
ConcurrentKeyspace: DashMap-backed keyspace with lock-free access--concurrentflag: enables the new moderoot cause analysis
the sharded architecture has significant channel overhead:
every request crosses thread boundaries twice. with DashMap, connection handlers access the keyspace directly without any channel coordination.
design considerations
this is a tradeoff:
the concurrent mode is marked experimental. full feature parity with the sharded mode would require more work (lists, hashes, sorted sets, persistence).
what was tested