queries, MapReduce, and resharding. • backup - A tablet that has stopped replication at a consistent snapshot, so it can upload a new backup for its shard. After it finishes, it will resume replication and be configured to avoid serving data from instances that are lagging beyond X seconds. For a true snapshot, queries must be sent to the master within a transaction. For read-after-write consistency, reading each query-part on a database snapshot and merging (without deduping) the results is equal to the set of rows obtained from executing the original query on the same snapshot with the rows containing NULL

queries, MapReduce, and resharding. • backup - A tablet that has stopped replication at a consistent snapshot, so it can upload a new backup for its shard. After it finishes, it will resume replication and be configured to avoid serving data from instances that are lagging beyond X seconds. For a true snapshot, queries must be sent to the master within a transaction. For read-after-write consistency, reading each query-part on a database snapshot and merging (without deduping) the results is equal to the set of rows obtained from executing the original query on the same snapshot with the rows containing NULL

queries, MapReduce, and resharding. • backup - A tablet that has stopped replication at a consistent snapshot, so it can upload a new backup for its shard. After it finishes, it will resume replication and be configured to avoid serving data from instances that are lagging beyond X seconds. For a true snapshot, queries must be sent to the master within a transaction. For read-after-write consistency, reading at present there are four. Point in Time Recovery leverages two Vitess features: 1. The use of SNAPSHOT keyspaces for recovery of the last backup before a requested specific timestamp to restore to. 2

@@version includes both the emulated MySQL version and the Vitess version, such as: 5.7.9-vitess-10.0.0-SNAPSHOT. This value can be changed by using the vtgate flag -mysql_server_version. Special functions There queries, MapReduce, and resharding. • backup - A tablet that has stopped replication at a consistent snapshot, so it can upload a new backup for its shard. After it finishes, it will resume replication and from the binlog. The aim is to be eventually (and rapidly) consistent with the current database snapshot. This improves performance since we will be merging multiple row updates into a single transaction

@@version includes both the emulated MySQL version and the Vitess version, such as: 5.7.9-vitess-10.0.0-SNAPSHOT. This value can be changed by using the vtgate flag -mysql_server_version. 21 Special functions queries, MapReduce, and resharding. • backup - A tablet that has stopped replication at a consistent snapshot, so it can upload a new backup for its shard. After it finishes, it will resume replication and from the binlog. The aim is to be eventually (and rapidly) consistent with the current database snapshot. This improves performance since we will be merging multiple row updates into a single transaction

queries, MapReduce, and resharding. • backup - A tablet that has stopped replication at a consistent snapshot, so it can upload a new backup for its shard. After it finishes, it will resume replication and from the binlog. The aim is to be eventually (and rapidly) consistent with the current database snapshot. This improves performance since we will be merging multiple row updates into a single transaction 54 The copy phase is nuanced: we copy a batch of rows until a particular PK using a consistent snapshot. However, once the copy is completed the binlog position would have moved possibly containing updates

@@version includes both the emulated MySQL version and the Vitess version, such as: 5.7.9-vitess-10.0.0-SNAPSHOT. This value can be changed by using the vtgate flag -mysql_server_version. Special functions There queries, MapReduce, and resharding. • backup - A tablet that has stopped replication at a consistent snapshot, so it can upload a new backup for its shard. After it finishes, it will resume replication and set of rows from the table with higher primary keys that the one copied so far using a consistent snapshot. This results in a stream of rows to be sent to the target which generates a bulk insert of these

queries, MapReduce, and resharding. • backup - A tablet that has stopped replication at a consistent snapshot, so it can upload a new backup for its shard. After it finishes, it will resume replication and be configured to avoid serving data from instances that are lagging beyond X seconds. For a true snapshot, queries must be sent to the master within a transaction. For read-after-write consistency, reading and comparing them against each other. This step can be done without the need to create special snapshot replicas. • Journaling (to be implemented): If there is any kind of traffic cut-over where we start

master —> vttablet • prepare two spare shard0, shard1 • vtgate point to origin master • multi-snapshot : data & repl-pos • multi-restore • set shard0, shard1 read-only. • shard0, shard1 replication shard0, shard1 origin shard0 shard1 origin shard0 shard1 vtgate [a-z] [a-m] [n-z] Vitess Snapshot • prepare • set read-only • stop slave • get master position & slave position. • flush