MariaDB 11.4/11.8 LTS pool-of-threads & Slow Plan Config

# MariaDB 11.4 LTS / 11.8 LTS High-Concurrency Production Configuration # Place at /etc/mysql/mariadb.conf.d/99-high-concurrency.cnf (32 GB RAM / 8 vCPU) [mariadb] # 1. Built-In Thread Pool (Prevents CPU context-switch collapse under connection spikes) thread_handling = pool-of-threads thread_pool_size = 8 thread_pool_max_threads = 512 thread_pool_stall_limit = 60 max_connections = 2500 extra_port = 3307 extra_max_connections = 10 # 2. InnoDB Memory & Single-File Redo Log innodb_buffer_pool_size = 22G innodb_log_file_size = 4G innodb_flush_method = O_DIRECT innodb_flush_log_at_trx_commit = 1 innodb_io_capacity = 4000 innodb_io_capacity_max = 8000 # 3. Disable Legacy Query Cache & Size Aria Internal Temp Engine query_cache_type = 0 query_cache_size = 0 aria_pagecache_buffer_size = 1G tmp_memory_table_size = 64M max_heap_table_size = 64M # 4. Optimizer Histograms & Deep Slow Query Diagnostics optimizer_use_condition_selectivity = 4 histogram_size = 254 slow_query_log = 1 long_query_time = 0.3 log_slow_verbosity = query_plan,innodb,explain