tcpdump mysql queries

If you have access to the MySQL server and logging is turned on then you have access to the queries as they are logged. Many production databases do not have logging turned on, simply because there are too many queries to handle. Also, there could be hundreds of servers hitting the logs at any given time, making it hard to see activity from a particular client. To take a look at MySQL queries as they leave a webserver you can use tcpdump and massage the output to get you what queries are being sent from that host.

# tcpdump -i eth0 -l -s 0 -w - dst port 3306 | stdbuf -o0 strings| stdbuf -o0 grep "SELECT\|INSERT\|UPDATE|\FROM\|WHERE\|ORDER\|AND\|LIMIT\|FROM\|SET\|COMMIT\|ROLLBACK"

Sometimes the query gets broken up into pieces if WHERE or LIMIT is used, and those pieces wind up on separate lines so we need to grep for them separately. Use stdbuf to force all the pipes to NOT buffer output, i.e. print output in pseudo real time.

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