[debian-mysql] Bug#910454: mysql-server: Restoring backup hangs for a large database

[Matthew Toseland]

Package: mysql-server
Version: 5.5.9999+default
Severity: normal

Dear Maintainer,

I am unable to restore a backup of a large database. Here I was
attempting to copy it by backing it up and restoring it.

What I did:

$ mysqldump --databases mythconverg > dump.myth
$ vi dump.myth
# Change the first few lines to change the name of the database from
# mythconverg to mythcopy and not fail if it already exists
$ mysql
MariaDB [(none)]> create database mythcopy;
MariaDB [(none)]> use mythcopy;
MariaDB [(none)]> source dump.myth;
...
Query OK, 21749 rows affected (0.22 sec)
Records: 21749  Duplicates: 0  Warnings: 0
...
Query OK, 21767 rows affected (0.20 sec)
Records: 21767  Duplicates: 0  Warnings: 0

There are lots of query records like the above, then it just stops, and
hangs for at least half an hour, probably forever.

I am able to use the mysql command line client on other databases, but not
on mythcopy. mysqld is not using any significant CPU or disk I/O according
to top and iotop. And /var/lib/mysql is on an SSD.

Googling shows a few bugs in the MySQL bug tracker, but nothing obvious
w.r.t. MariaDB, so there may be an upstream fix in MySQL but not
necessarily in  MariaDB.

-- System Information:
Debian Release: 9.5
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-8-amd64 (SMP w/6 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Init: systemd (via /run/systemd/system)

Versions of packages mysql-server depends on:
ii  default-mysql-server  1.0.2

mysql-server recommends no packages.

mysql-server suggests no packages.

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