MySQL – Why Does mysqldump Require DROP Command?

Rather than killing the process, it would be safer if you did it within MySQL:

$ mysqladmin processlist -u root -p
Enter password: 
+-----+------+-----------+-------------------+---------+------+-------+------------------+
| Id  | User | Host      | db                | Command | Time | State | Info             |
+-----+------+-----------+-------------------+---------+------+-------+------------------+
| 174 | root | localhost | example           | Sleep   | 297  |       |                  |
| 407 | root | localhost |                   | Query   | 0    |       | show processlist |
+-----+------+-----------+-------------------+---------+------+-------+------------------+

The query with id 174 is the one blocking deletion of the 'example' database, so before you kill any processes first let MySQL try to terminate the query:

$ mysqladmin kill 174

Run the processlist command above again to confirm that it was killed.

If this doesn't work, then you could perhaps look at killing the errant process, but before that you might try restarting the MySQL server.

You can also run commands like 'SHOW FULL PROCESSLIST' and 'KILL 174' in the MySQL shell, for example if you only have the MySQL client installed. The main point is to avoid killing the process using 'kill' in the shell unless absolutely necessary.

Generally speaking you can use either mysql or mysqladmin. You shouldn't need to be running commands like this that often though; once you start killing queries regularly something is definitely wrong and you'd be better off fixing that problem (killing the query process is just treating the symptom).

Your 1st mysqldump makes table structures and INSERTs and puts it in dump.sql.

Your 2nd dump is a remote dump that is piped straight into mysql in localhost.

If you are trying to catch any output based on errors, try this:

mysqldump -alv -h 123.123.123.123 --user=username --password=p@ssw0rd --add-drop-table databasename 2> output.log | mysql --user=username --password=p@ssw0rd -h localhost localdatabase

Using 2> will catch any error-based output (aka stderr). The mysqldump should still pipe normal console output (aka stdout) to the other mysql session and load the data as intended.

EXAMPLE : I have a small database called sample on my PC.

I ran this:

C:\LWDBA>mysqldump -u... -p... --verbose sample 2>sample.txt > sample.sql

C:\LWDBA>type sample.txt
-- Connecting to localhost...
-- Retrieving table structure for table users...
-- Sending SELECT query...
-- Retrieving rows...
-- Disconnecting from localhost...

C:\LWDBA>type sample.sql
-- MySQL dump 10.13  Distrib 5.5.12, for Win64 (x86)
--
-- Host: localhost    Database: sample
-- ------------------------------------------------------
-- Server version       5.5.12-log

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

--
-- Table structure for table `users`
--

DROP TABLE IF EXISTS `users`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `users_tbl_points` int(11) NOT NULL,
  `users_tbl_rank` int(11) NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`),
  KEY `users_tbl_points` (`users_tbl_points`)
) ENGINE=InnoDB AUTO_INCREMENT=31 DEFAULT CHARSET=latin1;
/*!40101 SET character_set_client = @saved_cs_client */;

--
-- Dumping data for table `users`
--

LOCK TABLES `users` WRITE;
/*!40000 ALTER TABLE `users` DISABLE KEYS */;
INSERT INTO `users` VALUES (1,785523,9),(2,443080,20),(3,858830,7),(4,964909,3),(5,248056,24),
(6,345553,21),(7,983596,2),(8,881325,6),(9,455836,19),(10,635204,16),(11,808514,8),
(12,136960,28),(13,259255,22),(14,885399,5),(15,649229,15),(16,589948,18),(17,2055,30),
(18,240429,25),(19,195981,26),(20,258620,23),(21,705158,12),(22,749931,11),(23,634182,17),
(24,921117,4),(25,703038,13),(26,751842,10),(27,650093,14),(28,994943,1),(29,24437,29),
(30,137355,27);
/*!40000 ALTER TABLE `users` ENABLE KEYS */;
UNLOCK TABLES;
/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

-- Dump completed on 2012-03-02 15:49:54

C:\LWDBA>

Give it a Try !!!