system RTO ￿ 30s and RPO = 0. • Massive data and high concurrency scenarios with high requirements for storage capacity, scalability, and concurrency As applications grow rapidly, the data surges. Traditional disabled. TiDB con- figuration file performance �→ . �→ committer �→ - �→ concurrency �→ Modified Controls the concurrency number for requests related to commit operations in the commit phase of a single means there are four threads for the task. TiKV con- figuration file incremental �→ -scan- �→ concurrency �→ Newly added Sets the maximum number of concurrent executions for the tasks of incremen- tally

Processing (MPP) · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 6726 17.10.2 Multi-version concurrency control (MVCC) · · · · · · · · · · · · · · · · · · · · · · · · 6726 17.11 O · · · · · · · · · centers, racks, and machines, ensuring system RTO ￿ 30 seconds and RPO = 0. • Massive data and high concurrency scenarios Traditional standalone databases cannot meet the data capacity requirements of rapidly (petabytes) level. • Real-time HTAP scenarios TiDB is ideal for scenarios with massive data and high concurrency that require real- time processing. TiDB introduces the TiFlash columnar storage engine in v4.0

system RTO ￿ 30s and RPO = 0. • Massive data and high concurrency scenarios with high requirements for storage capacity, scalability, and concurrency As applications grow rapidly, the data surges. Traditional allow-concurrent-memtable-write: true server.grpc-concurrency: 6 readpool.unified.min-thread-count: 5 readpool.unified.max-thread-count: 20 readpool.storage.normal-concurrency: 10 pessimistic-txn.pipelined: true TiDB TiDB global variable configuration set global tidb_hashagg_final_concurrency=1; set global tidb_hashagg_partial_concurrency=1; set global tidb_enable_async_commit = 1; set global tidb_enable_1pc = 1;

system RTO ￿ 30s and RPO = 0. • Massive data and high concurrency scenarios with high requirements for storage capacity, scalability, and concurrency As applications grow rapidly, the data surges. Traditional statement that includes an HashAgg operator causes out of memory (OOM), you can try to set the concurrency of this operator to 1 to trigger disk spill, which alleviates memory stress. User document, #25882 – Support automatically invalidating stale Regions in MPP queries • Tools – TiCDC * Add the concurrency limit to the incremental scan of kv client #1899 * TiCDC can always pull the old value internally

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 6702 17.7.2 Multi-version concurrency control (MVCC) · · · · · · · · · · · · · · · · · · · · · · · · 6702 17.8 O · · · · · · · · · · centers, racks, and machines, ensuring system RTO ￿ 30 seconds and RPO = 0. • Massive data and high concurrency scenarios Traditional standalone databases cannot meet the data capacity requirements of rapidly (petabytes) level. • Real-time HTAP scenarios TiDB is ideal for scenarios with massive data and high concurrency that require real- time processing. TiDB introduces the TiFlash columnar storage engine in v4.0

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 6546 17.7.2 Multi-version concurrency control (MVCC) · · · · · · · · · · · · · · · · · · · · · · · · 6546 17.8 O · · · · · · · · · · centers, racks, and machines, ensuring system RTO ￿ 30 seconds and RPO = 0. • Massive data and high concurrency scenarios Traditional standalone databases cannot meet the data capacity requirements of rapidly (petabytes) level. • Real-time HTAP scenarios TiDB is ideal for scenarios with massive data and high concurrency that require real- time processing. TiDB introduces the TiFlash columnar storage engine in v4.0

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 6603 17.7.2 Multi-version concurrency control (MVCC) · · · · · · · · · · · · · · · · · · · · · · · · 6603 17.8 O · · · · · · · · · · centers, racks, and machines, ensuring system RTO ￿ 30 seconds and RPO = 0. • Massive data and high concurrency scenarios Traditional standalone databases cannot meet the data capacity requirements of rapidly (petabytes) level. • Real-time HTAP scenarios TiDB is ideal for scenarios with massive data and high concurrency that require real- time processing. TiDB introduces the TiFlash columnar storage engine in v4.0

centers, racks, and machines, ensuring system RTO ￿ 30 seconds and RPO = 0. • Massive data and high concurrency scenarios Traditional standalone databases cannot meet the data capacity requirements of rapidly (petabytes) level. • Real-time HTAP scenarios TiDB is ideal for scenarios with massive data and high concurrency that require real- time processing. TiDB introduces the TiFlash columnar storage engine in v4.0 tidb_analyze_partition_concurrency �→ Modified Changes the default value from 1 to 2 after further tests. 42 Variable name Change type Description tidb_build_stats_concurrency �→ Modified Changes the

centers, racks, and machines, ensuring system RTO ￿ 30 seconds and RPO = 0. • Massive data and high concurrency scenarios Traditional standalone databases cannot meet the data capacity requirements of rapidly (petabytes) level. • Real-time HTAP scenarios TiDB is ideal for scenarios with massive data and high concurrency that require real- time processing. TiDB introduces the TiFlash columnar storage engine in v4.0 heartbeats and scheduling tasks. 37 If the cluster has many TiDB instances, and there is a high concurrency of requests for Region information, the CPU pressure on the PD leader increases further and might

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 6476 17.7.2 Multi-version concurrency control (MVCC) · · · · · · · · · · · · · · · · · · · · · · · · 6476 17.8 O · · · · · · · · · · centers, racks, and machines, ensuring system RTO ￿ 30 seconds and RPO = 0. • Massive data and high concurrency scenarios Traditional standalone databases cannot meet the data capacity requirements of rapidly (petabytes) level. • Real-time HTAP scenarios TiDB is ideal for scenarios with massive data and high concurrency that require real- time processing. TiDB introduces the TiFlash columnar storage engine in v4.0