A cluster rehearsal (PostgreSQL + NATS) left index tasks pending well past the one-hour task lock after the node that claimed them was stopped or killed. The exact cause there isn't confirmed; this closes every path found in the task manager that stretches a takeover past the lock, or keeps a task claimed without running it: - A graceful stop never released the locks it held, so every task the node had claimed stayed blocked for an hour. The server now tracks the locks it holds (common::ipc::TaskLocks) and, once the shutdown signal arrives, stops claiming and releases them before exiting. - A node that failed to claim a task (another node held it) set its own local hold for a full lock lifetime from that scan. If the holder claimed it just after the scan began, or ran on a clock ahead, that hold ran out a moment before the lock did and was set for another hour: two hours in all. Such claims are now tried again every five minutes (a twelfth of the lock lifetime), and the task manager wakes up for them: before, a node without a coordinator could sleep up to five minutes past the recheck, or until something else woke it. - A worker that panicked took its task type down on that node for good, while the scan kept claiming that type's tasks and failing to hand them over, re-taking each lock as it expired and so starving every other node of them. Each batch now runs on a task of its own; a panic is logged, the batch's locks are released and the worker carries on. A failed hand-over releases the lock too. - A claimed task the worker couldn't read, or found gone, kept its lock for the hour. It is released. - An IndexDocument task for a file (not indexed) returned no result, which shifted every later result in the batch onto the wrong task in update_tasks. It returns Ignored. Nothing queues such a task today. The lock lifetime stays one hour; it now lives per server so the tests can shorten it. store::task_locks::task_lock_tests plays a second node by writing its locks straight into the in-memory store: tasks it claimed and abandoned run here once its locks expire, including locks that outlive this node's view of them, and a graceful stop hands this node's locks back at once and claims nothing more. It passes on RocksDB, SQLite and PostgreSQL. With the old recheck it fails.