yum error solution

if you encounter this error when using yum, try yum clean all, and then
rerun the job. It will be OK.

Downloading Packages:
Traceback (most recent call last):
File "/usr/bin/yum", line 29, in <module>
yummain.user_main(sys.argv[1:], exit_code=True)
File "/usr/share/yum-cli/yummain.py", line 258, in user_main
errcode = main(args)
File "/usr/share/yum-cli/yummain.py", line 196, in main
return_code = base.doTransaction()
File "/usr/share/yum-cli/cli.py", line 456, in doTransaction
problems = self.downloadPkgs(downloadpkgs,
callback_total=self.download_callback_total_cb)
File "/usr/lib/python2.6/site-packages/yum/__init__.py", line 1756, in
downloadPkgs
self.plugins.run('predownload', pkglist=pkglist)
File "/usr/lib/python2.6/site-packages/yum/plugins.py", line 183, in run
func(conduitcls(self, self.base, conf, **kwargs))
File "/usr/lib/yum-plugins/axelget.py", line 280, in predownload_hook
downloaded_drpm_pkgs = download_drpm(conduit)
File "/usr/lib/yum-plugins/axelget.py", line 66, in download_drpm
presto_info[repo.id] = presto.PrestoParser(filename).getDeltas()
File "/usr/lib/yum-plugins/presto.py", line 509, in __init__
for event, elem in iterparse(fo):
File "<string>", line 61, in __iter__
File "/usr/lib64/python2.6/gzip.py", line 219, in read
self._read(readsize)
File "/usr/lib64/python2.6/gzip.py", line 271, in _read
uncompress = self.decompress.decompress(buf)
zlib.error: Error -3 while decompressing: invalid distance too far back

mysql security related sqls

show all users in mysql
select host, user, password from mysql.user;

grant all privilege to root from localhost
grant all on * to 'root'@'localhost';

grant all privilege to user_a from all hosts
grand all on * to 'user_a'@'%';