MySQL – Troubleshooting Incomplete Mysqldump Backups

backupinnodbMySQLmysqldump

I'm trying to run mysqldump to create a database snapshot, and I'm finding it will randomly stop midway, without reporting any error. My database is relatively small (about 100MB) and is using InnoDB.

I'm running it like:

mysqldump --force --single-transaction --quick --user myuser --password=mypass -h mydatabasehost mydb > /tmp/snapshot.sql

Checking the exit code reports 0.

My version is: mysqldump Ver 10.13 Distrib 5.1.52, for redhat-linux-gnu (i386)

I've seen some similar posts and even an official bug report, but neither solutions seem to apply.

How to I get mysqldump to take a complete database snapshot?

EDIT: My database currently resides on Amazon's RDS.

Best Answer

It may have been a problem with max_allowed_packet not being set high enough on both the client (i.e. mysqldump) and the server (i.e. Amazon RDS). I set this to 500M on both and that seems to have fixed the problem.

Since InnoDB's information schema tables only give row count estimates, it's hard to tell if my snapshot truly includes everything from RDS. All the tables are there, but the row counts differ. I'll update with a more definitive answer when I have some time to script a more thorough analysis.

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MySQLDump wrong dump

Just reading the header you put in the question shows something interesting. In fact, the question shows three things:

MySQL dump 10.13 Distrib 5.1.34, for apple-darwin9.5.0 (i386) indicates you used mysqldump from apple-darwin9.5.0 (i386) binaries
Server version 5.0.51a-24+lenny2 shows the version of mysql you used mysqldump to dump from.
You wanted to load the mysqldump file into Ver 14.14 Distrib 5.1.57, for apple-darwin10.3.0 (i386) using readline 5.1

What a jumble of versions to do this with.

If you want to see if mysqldump has an issue with the line that has DATEDIFF, try dumping just the schema.

mysqldump --no-data --all-databases ... > MySQLSchema.sql

This will display ony the schema. No INSERTs will be in the output. You can then hunt down that lines. You may also want to dump the data onyl without the schema,

mysqldump --no-create-info --all-databases ... > MySQLData.sql

Splitting the dumps allows you to load the schema into an editor and see if there are any problems. If you do not see any problems, load the MySQLSchema.sql into the target server. If the error is reproduced, you can fix the schema file and reload. Once the schema is loaded, you can separate load MySQLData.sql

BTW you should use mysqldump binary whose version is 5.0.51a-24+lenny2. Use dumps from version as mysqld is usually better to port and may minimize problems like this.

Give it a Try !!!

Mysql – Incomplete MYSQL Dumps

Use the -v (or --verbose) option for mysqdump which can show the errors that occur

Best Answer

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MySQLDump wrong dump

Mysql – Incomplete MYSQL Dumps

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