How pt-table-checksum works?
pt-table-checksum connects to the server you specify, and finds databases and tables that match the filters you specify (if any). It works one table at a time, so it does not accumulate large amounts of memory or do a lot of work before beginning to checksum. This makes it usable on very large servers.
What are the advanced replication technologies that MySQL 8 possesses?
Relevant replication areas that have been improved in MySQL 8: Observability: more replication applier queuing details; improved tracing for Group Replication; replication filters statistics; additional cluster statistics on group replication; enhanced visibility into row-based replication.
What is replication delay?
Replication lag occurs when the slaves (or secondaries) cannot keep up with the updates occuring on the master (or primary). Unapplied changes accumulate in the slaves’ relay logs and the version of the database on the slaves becomes increasingly different from that of the master.
How does PT-table checksum-Percona check replication?
pt-table-checksum performs an online replication consistency check by executing checksum queries on the master, which produces different results on replicas that are inconsistent with the master. The optional DSN specifies the master host.
Is there a backwards compatible version of PT-table checksum?
The table referenced in that query is the checksum table, where the checksums are stored. Each row in the table contains the checksum of one chunk of data from some table in the server. Version 2.0 of pt-table-checksum is not backwards compatible with pt-table-sync version 1.0. In some cases this is not a serious problem.
Which is faster PT table checksum or MD5?
Take into consideration that by default, pt-table-checksum use CRC32 checksums. CRC32 is not a cryptographic algorithm and for that reason it is prone to have collisions. On the other hand, CRC32 algorithm is faster and less CPU-intensive than MD5 and SHA1.