0

I'm using Percona's Xtrabackup tools to back up a database nightly. I wrote a wrapper script to keep the proper number of backups around, write the output to a log file, and email the log file if the backup dies. When I manually run the script as root, the log file is generated as expected. However, once I put it in cron, the log file is created, but no content is generated. Here's the relevant portion of the script (let me know if I should post the whole thing.

DATE=`date +%F-%H%M` LOC=/var/mysqlbackups/dbBackup-$DATE LOGLOC="$LOC.log" /usr/bin/innobackupex --user=$SQLUSER --password=$SQLPASSWORD --no-timestamp $LOC &>>$LOGLOC if [ $? -ne 0 ] then CONTENT="Backup Failed. Log information below.\n\n--------------------------------------------------------\n$CONTENT" CONTENT+=`cat $LOGLOC` echo -e "$CONTENT" | mail -s "Backup on DB3 failed" [email protected] exit 1 fi

Here's the crontab entry in root's crontab:

5 1 * * * /usr/local/sbin/dbBackup.sh

And the resulting directories/files. Not that on 1/28 I ran it manually, then on 1/29 it was run by cron:

drwxr-xr-x 5 root root 4096 Jan 28 10:18 dbBackup-2015-01-28-1010 -rw-r--r-- 1 root root 21441 Jan 28 10:18 dbBackup-2015-01-28-1010.log drwxr-xr-x 5 root root 4096 Jan 29 01:14 dbBackup-2015-01-29-0105 -rw-r--r-- 1 root root 0 Jan 29 01:05 dbBackup-2015-01-29-0105.log

I've asked the Googles, but haven't had any luck identifying the problem. Any help would be appreciated.

Improve this question
2
  • did you declare SQLUSER and SQLPASSWORD? It does not seem to be declared in the script. Commented Jan 30, 2015 at 19:00
  • What kind of script? E.g., bash or shell? Commented Jan 30, 2015 at 19:01

2 Answers 2

Reset to default
0

I see two possibilities here. One, I strongly recommend using full paths for all commands in cron jobs - e.g. /usr/bin/cat instead of cat. Two, your shell may be a more restrictive one in the cron environment where the string += syntax doesn't work. Try to figure a way around that somehow - I'm not sure how off the top of my head, but cat'ing to another file would be where I would start.

Improve this answer
1
  • I'm not sure that either apply - the trouble happens before that, as the log file in the filesystem itself is emtpy. Your response did make me think though - I wonder if the problem is with using &>> for redirection. I'll try with more traditional IO redirection and report back. Commented Jan 30, 2015 at 19:13
0

It turns out that using IO redirection that only bash supports was breaking the script when it ran in cron. I switched to the old school 2>&1 syntax, and the problem is solved.

Improve this answer

You must log in to answer this question.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.