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5bbda97111
crash recovery Summary ======= When doing server recovery, the active transactions will be rolled back by InnoDB background rollback thread automatically. The prepared transactions will be committed or rolled back accordingly by binlog recovery. Binlog recovery is done in main thread before the server can provide service to users. If there is a big transaction to rollback, the server will not available for a long time. This patch provides a way to rollback the prepared transactions asynchronously. Thus the rollback will not block server startup. Design ====== - Handler::recover_rollback_by_xid() This patch provides a new handler interface to rollback transactions in recover phase. InnoDB just set the transaction's state to active. Then the transaction will be rolled back by the background rollback thread. - Handler::signal_tc_log_recover_done() This function is called after tc log is opened(typically binlog opened) has done. When this function is called, all transactions will be rolled back have been reverted to ACTIVE state. Thus it starts rollback thread to rollback the transactions. - Background rollback thread With this patch, background rollback thread is defered to run until binlog recovery is finished. It is started by innobase_tc_log_recovery_done().
53 lines
1.5 KiB
Plaintext
53 lines
1.5 KiB
Plaintext
CREATE TABLE t1 (id int primary key, data int) ENGINE = InnoDB;
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INSERT INTO t1 VALUES (0, 1);
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#
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# 1. Check DML in prepared state can rollback correctly.
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#
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connect con1, localhost, root,,;
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SET debug_sync = "ha_commit_trans_after_prepare SIGNAL prepared1 WAIT_FOR continue";
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INSERT INTO t1 VALUES(1, 1);;
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connect con2, localhost, root,,;
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SET debug_sync = "now WAIT_FOR prepared1";
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SET debug_sync = "ha_commit_trans_after_prepare SIGNAL prepared2 WAIT_FOR continue";
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UPDATE t1 SET data = data + 1 WHERE id = 0;
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connection default;
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SET debug_sync = "now WAIT_FOR prepared2";
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# Kill the server
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disconnect con1;
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disconnect con2;
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# restart
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# Expect (0, 1)
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SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
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SELECT * FROM t1;
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id data
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0 1
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INSERT INTO t1 VALUES(1, 1);
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UPDATE t1 SET data = data + 1 WHERE id = 0;
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# Expect (0, 2), (1, 1)
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SELECT * FROM t1;
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id data
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0 2
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1 1
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#
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# 2. Test that innodb shutdown as expected if any error happens before
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# normal rollback task is started. In the situation, rollback task
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# should be started at preshutdown accordingly to rollback or
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# deregister all recovered active transactions.
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#
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INSERT INTO t1 SELECT seq + 2, 1 FROM seq_1_to_1024;
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BEGIN;
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UPDATE t1 SET data = 10;
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SET GLOBAL innodb_log_checkpoint_now = 1;
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# Kill the server
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# restart: --innodb-read-only
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SELECT count(*) FROM information_schema.innodb_trx;
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count(*)
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1
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# Kill the server
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# restart: --innodb-read-only
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SELECT count(*) FROM information_schema.innodb_trx;
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count(*)
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1
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# restart
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DROP TABLE t1;
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