This article explains the concept of deadlocks, outlines the four necessary conditions, and demonstrates a step‑by‑step Linux workflow using pstack and gdb together with a sample pthread program to identify, analyze, and fix cross‑locking deadlock scenarios.
The article explains what deadlocks are, compares spinlocks and semaphores, describes typical deadlock scenarios in the Linux kernel, and details the built‑in detection mechanisms such as hung‑task (D‑state) and soft‑lockup (R‑state) along with the NMI watchdog for long interrupt disabling.
This article examines three real‑world MySQL deadlock incidents—unique‑key null insertion, concurrent duplicate‑key insertion, and a JDBC parameter bug—detailing their detection, analysis, and the concrete fixes applied to prevent recurrence.
A MySQL 5.5 server on CentOS 6.7 hung because two internal mutexes (LOCK_index and LOCK_thread_count) deadlocked during concurrent purge binlog and reset master commands, and the issue was resolved by upgrading to a version where the bug is fixed.
This article explains MySQL InnoDB's locking mechanisms—including MVCC snapshot vs. current reads, two‑phase locking, isolation levels, lock types, GAP locks, and deadlock scenarios—by analyzing simple and complex SQL examples and showing how different index and isolation configurations affect lock acquisition.
This article explains what a deadlock is, outlines its four necessary conditions, provides a sample pthread program that deadlocks, and shows step‑by‑step how to use pstack and gdb on Linux to identify the stuck threads and understand the root cause.
This article explains Oracle deadlock fundamentals, classifies row‑level and block‑level (ITL) deadlocks, shows how to read trace files in both single‑instance and RAC environments, and provides step‑by‑step simulations that reveal root causes and practical mitigation techniques.
This article explains how deadlocks arise in Linux kernels, compares spinlocks and semaphores, and details the kernel's built‑in D‑state, R‑state, and long‑interrupt‑disable detection mechanisms such as hung‑task, soft‑lockup, and NMI watchdog, including key code snippets.
A deep dive into a long‑standing PHP‑CGI deadlock that left deleted log files occupying disk space, explaining how signal‑unsafe functions caused the lock, how the issue was diagnosed with lsof, strace and gdb, and the practical steps to eliminate the deadlock.
This article explains the theory behind SQL Server's parallel execution, illustrates its performance gains with Amdahl's Law, lists operators that block parallelism, discusses configuration settings, warns of deadlocks and thread starvation, and presents practical MapReduce‑style optimizations for real‑world workloads.
This article analyzes a puzzling MySQL deadlock scenario where concurrent DELETE statements on a uniquely indexed row lead to a deadlock, explaining the lock modes, InnoDB's deadlock‑prevention strategy, and the conditions that make such deadlocks possible.
This article provides an in‑depth analysis of MySQL/InnoDB locking mechanisms, covering MVCC snapshot vs current reads, cluster indexes, two‑phase locking, isolation levels, lock behavior for simple and complex SQL statements, and practical deadlock diagnosis techniques.
The article explains how concurrent transactions can cause deadlocks when resources are locked, and introduces the Actor model—combining data, behavior, and message passing—to give data its own active logic, thereby naturally handling concurrency and avoiding such deadlocks.
A metaphorical story follows a newly created thread as it learns about extracting request parameters, performing login, handling CPU scheduling, using caches, encountering deadlocks, and ultimately witnessing a system reboot, illustrating core concepts of multithreading, concurrency control, and thread‑pool lifecycle.
This report details a series of MySQL InnoDB experiments that examine transaction locking, lock types, gap and next‑key locks, and deadlock behavior across various SQL operations, providing practical insights for optimizing concurrency and preventing deadlocks.
This article explains what a deadlock is, why it occurs, the four necessary conditions that enable it, and outlines common strategies—including ignoring, detection and recovery, avoidance, and prevention—to manage or eliminate deadlocks in operating systems.
