Amazon RDS mysqbinlog Error – Could Not Find First Log File Name

amazon-rdsawsMySQL

Preamble:

We use RDS at AWS to manage our MySQL database. I know that RDS creates binary logs used for replication..
I want to harvest these binary logs and store them on S3, so that at any time, i can restore to an off-site database and replay the actions.

The Problem:

I span up a new RDS instance, and tried the following.

root@aws_test_server:/root# mysqlbinlog -h testing.xxxxxxxx.eu-west-1.rds.amazonaws.com -u myuser -p --read-from-remote-server -t mysql-bin-changelog.000002
Enter password:
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!40019 SET @@session.max_insert_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
ERROR: Got error reading packet from server: Could not find first log file name in binary log index file
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
root@aws_test_server:/root#

So the binary log retrieves fine, however see the Error within the binary log..
What does this mean?

I googled for about 2 days and could find no mention of this error [anywhere].

My questions:

Is this a good idea? (backing up binary logs to S3..)
Can it be done in a better way? (~infinite point-in-time db recovery)
What can I do about the error?

PS: this is happening for the production DB and this test DB

PS2: I note that this is not directly a programming question, however is related to it. Please do not move/close from SO to somewhere like serverfault. Thanks

Update 2/4/2014:

SHOW BINARY LOGS;

mysql> show binary logs;
+----------------------------+-----------+
| Log_name                   | File_size |
+----------------------------+-----------+
| mysql-bin-changelog.000002 |      1097 |
| mysql-bin-changelog.000003 |       469 |
| mysql-bin-changelog.000004 |       469 |
| mysql-bin-changelog.000005 |       594 |
| mysql-bin-changelog.000006 |       715 |
| mysql-bin-changelog.000007 |       412 |
+----------------------------+-----------+
6 rows in set (0.00 sec)

SHOW MASTER STATUS;

mysql> show master status;
+----------------------------+----------+--------------+------------------+-------------------+
| File                       | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+----------------------------+----------+--------------+------------------+-------------------+
| mysql-bin-changelog.000007 |      412 |              |                  |                   |
+----------------------------+----------+--------------+------------------+-------------------+
1 row in set (0.01 sec)

Command: mysqlbinlog -R -h $HOST -u ttc -p -j 0 --stop-position=412 -r file

Result:

Enter password:
Warning: option 'start-position': unsigned value 0 adjusted to 4
mysqlbinlog Ver 3.3 for debian-linux-gnu at x86_64
Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Dumps a MySQL binary log in a format usable for viewing or for piping to
the mysql command line client.

Usage: mysqlbinlog [options] log-files
  -?, --help          Display this help and exit.
  --base64-output[=name]
                      Determine when the output statements should be
                      base64-encoded BINLOG statements: 'never' disables it and
                      works only for binlogs without row-based events;
                      'decode-rows' decodes row events into commented SQL
                      statements if the --verbose option is also given; 'auto'
                      prints base64 only when necessary (i.e., for row-based
                      events and format description events); 'always' prints
                      base64 whenever possible. 'always' is deprecated, will be
                      removed in a future version, and should not be used in a
                      production system.  --base64-output with no 'name'
                      argument is equivalent to --base64-output=always and is
                      also deprecated.  If no --base64-output[=name] option is
                      given at all, the default is 'auto'.
  --character-sets-dir=name
                      Directory for character set files.
  -d, --database=name List entries for just this database (local log only).
  --debug-check       Check memory and open file usage at exit .
  --debug-info        Print some debug info at exit.
  --default-auth=name Default authentication client-side plugin to use.
  -D, --disable-log-bin
                      Disable binary log. This is useful, if you enabled
                      --to-last-log and are sending the output to the same
                      MySQL server. This way you could avoid an endless loop.
                      You would also like to use it when restoring after a
                      crash to avoid duplication of the statements you already
                      have. NOTE: you will need a SUPER privilege to use this
                      option.
  -F, --force-if-open Force if binlog was not closed properly.
                      (Defaults to on; use --skip-force-if-open to disable.)
  -f, --force-read    Force reading unknown binlog events.
  -H, --hexdump       Augment output with hexadecimal and ASCII event dump.
  -h, --host=name     Get the binlog from server.
  -l, --local-load=name
                      Prepare local temporary files for LOAD DATA INFILE in the
                      specified directory.
  -o, --offset=#      Skip the first N entries.
  -p, --password[=name]
                      Password to connect to remote server.
  --plugin-dir=name   Directory for client-side plugins.
  -P, --port=#        Port number to use for connection or 0 for default to, in
                      order of preference, my.cnf, $MYSQL_TCP_PORT,
                      /etc/services, built-in default (3306).
  --protocol=name     The protocol to use for connection (tcp, socket, pipe,
                      memory).
  -R, --read-from-remote-server
                      Read binary logs from a MySQL server.
  -r, --result-file=name
                      Direct output to a given file.
  --server-id=#       Extract only binlog entries created by the server having
                      the given id.
  --set-charset=name  Add 'SET NAMES character_set' to the output.
  -s, --short-form    Just show regular queries: no extra info and no row-based
                      events. This is for testing only, and should not be used
                      in production systems. If you want to suppress
                      base64-output, consider using --base64-output=never
                      instead.
  -S, --socket=name   The socket file to use for connection.
  --start-datetime=name
                      Start reading the binlog at first event having a datetime
                      equal or posterior to the argument; the argument must be
                      a date and time in the local time zone, in any format
                      accepted by the MySQL server for DATETIME and TIMESTAMP
                      types, for example: 2004-12-25 11:25:56 (you should
                      probably use quotes for your shell to set it properly).
  -j, --start-position=#
                      Start reading the binlog at position N. Applies to the
                      first binlog passed on the command line.
  --stop-datetime=name
                      Stop reading the binlog at first event having a datetime
                      equal or posterior to the argument; the argument must be
                      a date and time in the local time zone, in any format
                      accepted by the MySQL server for DATETIME and TIMESTAMP
                      types, for example: 2004-12-25 11:25:56 (you should
                      probably use quotes for your shell to set it properly).
  --stop-position=#   Stop reading the binlog at position N. Applies to the
                      last binlog passed on the command line.
  -t, --to-last-log   Requires -R. Will not stop at the end of the requested
                      binlog but rather continue printing until the end of the
                      last binlog of the MySQL server. If you send the output
                      to the same MySQL server, that may lead to an endless
                      loop.
  -u, --user=name     Connect to the remote server as username.
  -v, --verbose       Reconstruct SQL statements out of row events. -v -v adds
                      comments on column data types.
  -V, --version       Print version and exit.
  --open-files-limit=#
                      Used to reserve file descriptors for use by this program.

Variables (--variable-name=value)
and boolean options {FALSE|TRUE}  Value (after reading options)
--------------------------------- ----------------------------------------
base64-output                     (No default value)
character-sets-dir                (No default value)
database                          (No default value)
debug-check                       FALSE
debug-info                        FALSE
default-auth                      (No default value)
disable-log-bin                   FALSE
force-if-open                     TRUE
force-read                        FALSE
hexdump                           FALSE
host                              ttc-testing.cz6c92dfxwoh.eu-west-1.rds.amazonaws.com
local-load                        (No default value)
offset                            0
plugin-dir                        (No default value)
port                              3306
read-from-remote-server           TRUE
server-id                         0
set-charset                       (No default value)
short-form                        FALSE
socket                            /var/run/mysqld/mysqld.sock
start-datetime                    (No default value)
start-position                    4
stop-datetime                     (No default value)
stop-position                     412
to-last-log                       FALSE
user                              ttc
open-files-limit                  64

Best Answer

You are mistaken in your assertion that "the binary log retrieves fine." The output you are seeing is boilerplate output from mysqlbinlog... there's no evidence here that you are actually fetching the binlog. There's no such log file on the server. That's the meaning of this error.

SHOW BINARY LOGS;

...to find the available logs on the server.

You can confirm that you are not in fact actually fetching a file, by passing a completely bogus binlog file name and I suspect the output will be the same.

Backing up binlogs is an excellent plan, but you should look into the --stop-never option that, if I recall correctly, was introduced in the version of mysqlbinlog that shipped with MySQL Server 5.6 (backwards compatible with all 5.x servers) and maintains a connection to the server and fetches the files, saving each one under its own name.

Related Solutions

Mysql – Looking for an efficient way to fix “Could not parse relay log event entry…” error

There is more stable approach you can try

Here is something to remember

Whenever you run CHANGE MASTER TO, it will erase every relay log you have. You do not want to keep relay logs of commands you have not executed any SQL on as of yet

The following is an excerpt taken from a post I made back on Feb 03, 2012 : How to resolve the master server shut down/unavailability in mysql with master - slave replication :

Please notice that there are two sets of replication coordinates from the Master

(Master_Log_File,Read_Master_Log_Pos)

(Relay_Master_Log_File,Exec_Master_Log_Pos)

There is a major difference between them

(Master_Log_File,Read_Master_Log_Pos) tells you the last binlog statement from the Master's log file and log position that the Slave read from the Master and placed in its Relay Logs.

(Relay_Master_Log_File,Exec_Master_Log_Pos) tells you the last binlog statement from the Master's log file and log position that the Slave read from the Master and placed in its Relay Logs THAT IS NEXT TO BE EXECUTED ON THE SLAVE.

What you want are two things:

Erase Every Binary Log You Have
Start Collecting Binary Log Entries From the Last SQL You Successfully Executed.

In your case, you must use the second set of Replication Coordinates

Relay_Master_Log_File
Exec_Master_Log_Pos

It is easy to distrust a corrupt relay log as shown in the error message. The one that hurts the most is a corrupt Master Log. You will have to jump through hoops if that is the case. On the other hand, if one of the other situations was the reason for the corrupt relay log, the simplest and most concise approach is what I stated.

To make sure, whatever is reported for Relay_Master_Log_File, if that particular binary log still exists on the Master, perform a mysqlbinlog on it. If it dumps in its entirety without corrupt characters, go ahead and use the second set of replication coordinates.

From my same earlier post

mysql> show slave status\G
*************************** 1. row ***************************
             Slave_IO_State: Waiting for master to send event
                Master_Host: 10.48.20.253
                Master_User: replicant
                Master_Port: 3306
              Connect_Retry: 60
            Master_Log_File: mysql-bin.000254
        Read_Master_Log_Pos: 858190247
             Relay_Log_File: relay-bin.066069
              Relay_Log_Pos: 873918
      Relay_Master_Log_File: mysql-bin.000254
           Slave_IO_Running: Yes
          Slave_SQL_Running: Yes
            Replicate_Do_DB:
        Replicate_Ignore_DB:
         Replicate_Do_Table:
     Replicate_Ignore_Table:
    Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
                 Last_Errno: 0
                 Last_Error:
               Skip_Counter: 0
        Exec_Master_Log_Pos: 858190247
            Relay_Log_Space: 873772
            Until_Condition: None
             Until_Log_File:
              Until_Log_Pos: 0
         Master_SSL_Allowed: No
         Master_SSL_CA_File:
         Master_SSL_CA_Path:
            Master_SSL_Cert:
          Master_SSL_Cipher:
             Master_SSL_Key:
      Seconds_Behind_Master: 0
1 row in set (0.00 sec)

notice that the Replication Coordinates from SHOW SLAVE STATUS\G for what was last executed are (mysql-bin.000254,858190247). The CHANGE MASTER TO command in this case would be:

CHANGE MASTER TO master_log_file='mysql-bin.000254',master_log_pos=858190247;

Give it a Try !!!

UPDATE 2012-09-14 16:38 EDT

If you worried about the stockpiling relay logs, just throttle the relay logs. In SHOW SLAVE STATUS\G, there is a field called Relay_Log_Space. That gives you the sum of all relay sizes in bytes. Did you know you could put a cap on that number ?

The option is called relay_log_space_limit.

For example, if you want to cap the total number of bytes to 10G, do the following

STEP 01) Add this to /etc/my.cnf on the Slave

[mysqld]
relay_log_space_limit = 10G

STEP 02) Run service mysql restart on the Slave

and that's it !!!

When the oldest relay has all its entries processed, it is deleted and a new relay log is created. That gets filled until all relay logs add up to 10G. That's the only way to control runaway relay log space issues.

UPDATE 2012-09-14 18:10 EDT

SUGGESTION : If you make mysqldump backups of the data on the Slave every midnight, you could set up the following to restrict having 1TB of binary logs:

STEP 01) Add this to /etc/my.cnf on the Master

[mysqld]
expire_logs_days = 14

STEP 02) Run this query on the Master

mysql> PURGE BINARY LOGS BEFORE DATE(NOW()) - INTERVAL 14 DAY;

STEP 03) service mysql restart on the Master

STEP 04) Add a mysqldump backup script to a crontab on the Slave

This will make the Slave more useful and would control having excess binary logs to worry about

MySQL Slave Relay Logging but not logging Binary Log

You forgot one thing

binlog-do-db=our_database  
binlog-ignore-db=mysql  
binlog-ignore-db=test  
replicate-do-db=our_database  
log-slave-updates

The option log-slave-updates takes SQL that was read from relay logs and records them in the Slave Binary Logs when the SQL is completed.

Please be very careful. You should never use binlog-do-db and binlog-ignore-db simultaneously. I wrote about this back on Jun 14, 2012 ( Configured MySQL replication but its not working ) which points to an old Percona article on binlog-do-db being dangerous.

SUGGESTION

Of the things you are using, you only need these lines

replicate-do-db=our_database  
log-slave-updates

You really don't need binlog-do-db=our_database once you have log-slave-updates working properly.