startup. With both auto-retry mechanisms disabled, TiDB 2.1.8 through 3.0.0-beta.1-40 passed our tests for snapshot iso- lation and single-key linearizability. 3.0.0-rc.2, which disables auto-retry by some invariants. We tested TiDB 2.1.7, 2.1.8, 3.0.0-beta.1, 3.0.0-beta.1- 40, and 3.0.0-rc.2. Our tests ran on a five-node De- bian Stretch cluster, with PD, TiKV, and TiDB on each node. We used a replication and CLOCK_MONOTONIC, running up to 5x faster than oth- ers. PingCAP had written their own Jepsen tests, which we reviewed and expanded upon during our collabo- ration. The resulting test suite encompasses

sists the vari- able value to the cluster. Changes the default value from OFF to ON after further tests, which means that the op- timizer is al- lowed to push Projection �→ down to the TiKV copro- cessor maintains compatibility with its newer versions. PingCAP will pe- riodically conduct compatibility tests with the latest version of Third- party tools supported by TiDB. • Compatible: indicates that because maintains compatibility with its newer versions. Ping- CAP will periodically conduct compatibility tests with the latest version of the tool. • Compatible: Indicates that because the corresponding third-party

maintains compatibility with its newer versions. PingCAP will pe- riodically conduct compatibility tests with the latest version of Third- party tools supported by TiDB. • Compatible: indicates that because maintains compatibility with its newer versions. Ping- CAP will periodically conduct compatibility tests with the latest version of the tool. • Compatible: Indicates that because the corresponding third-party describes how to test TiDB using TPC-C. TPC-C is an online transaction processing (OLTP) benchmark. It tests the OLTP system by using a commodity sales model that involves the following five transactions of

maintains compatibility with its newer versions. PingCAP will pe- riodically conduct compatibility tests with the latest version of Third- party tools supported by TiDB. • Compatible: indicates that because maintains compatibility with its newer versions. Ping- CAP will periodically conduct compatibility tests with the latest version of the tool. • Compatible: Indicates that because the corresponding third-party describes how to test TiDB using TPC-C. TPC-C is an online transaction processing (OLTP) benchmark. It tests the OLTP system by using a commodity sales model that involves the following five transactions of

maintains compatibility with its newer versions. PingCAP will pe- riodically conduct compatibility tests with the latest version of Third- party tools supported by TiDB. • Compatible: indicates that because maintains compatibility with its newer versions. Ping- CAP will periodically conduct compatibility tests with the latest version of the tool. • Compatible: Indicates that because the corresponding third-party describes how to test TiDB using TPC-C. TPC-C is an online transaction processing (OLTP) benchmark. It tests the OLTP system by using a commodity sales model that involves the following five transactions of

significantly �→ improve the restore speed of large datasets in large-scale clusters. �→ Real-world tests show that this feature can saturate the download �→ bandwidth, with the download speed improving by maintains compatibility with its newer versions. PingCAP will pe- riodically conduct compatibility tests with the latest version of Third- party tools supported by TiDB. • Compatible: indicates that because maintains compatibility with its newer versions. Ping- CAP will periodically conduct compatibility tests with the latest version of the tool. • Compatible: Indicates that because the corresponding third-party

significantly �→ improve the restore speed of large datasets in large-scale clusters. �→ Real-world tests show that this feature can saturate the download �→ bandwidth, with the download speed improving by maintains compatibility with its newer versions. PingCAP will pe- riodically conduct compatibility tests with the latest version of Third- party tools supported by TiDB. • Compatible: indicates that because maintains compatibility with its newer versions. Ping- CAP will periodically conduct compatibility tests with the latest version of the tool. • Compatible: Indicates that because the corresponding third-party

use this feature with TiCDC. After pausing data replication and conducting pre-online read-write tests in your down- stream TiDB cluster, this feature allows the cluster to gracefully and quickly roll tidb_auto_analyze_partition_batch_size �→ Modified Changes the default value from 1 to 128 after further tests. tidb_sysproc_scan_concurrency �→ Modified In a large- scale cluster, the concur- rency of scan maintains compatibility with its newer versions. PingCAP will pe- riodically conduct compatibility tests with the latest version of Third- party tools supported by TiDB. • Compatible: indicates that because

significantly �→ improve the restore speed of large datasets in large-scale clusters. �→ Real-world tests show that this feature can saturate the download �→ bandwidth, with the download speed improving by maintains compatibility with its newer versions. PingCAP will pe- riodically conduct compatibility tests with the latest version of Third- party tools supported by TiDB. • Compatible: indicates that because maintains compatibility with its newer versions. Ping- CAP will periodically conduct compatibility tests with the latest version of the tool. • Compatible: Indicates that because the corresponding third-party

from 1 to 2 after further tests. 42 Variable name Change type Description tidb_build_stats_concurrency �→ Modified Changes the default value from 4 to 2 after further tests. tidb_merge_partition_stats_concurrency TiCDC case- �→ sensitive �→ Modified Changes the default value from true to false after further tests, which means that the table names and database names in the TiCDC configu- ration file are case- insensitive Improve the performance of adding indexes with tidb_ddl_enable_fast_reorg �→ enabled. In internal tests, v7.5.0 improves the performance by up to 62.5% compared with v6.5.0. #47757 @tangenta • TiKV •