/var keeps filling due to yum cache

the /var/cache directory keeps filling frequently due to yum metadata in centos 7.5 server. most of the space utilized by the below files. i have set keep cache to 0 in /etc/yum.conf as well. but still not resolved. someone please throw somelight on this issue to rectify the same.

[4.0K]  centos7-x86_64-updates
[   0]  cachecookie
[ 52M]  filelists.xml.gz
[4.0K]  gen
[535M]  filelists.xml
[252M]  filelists.xml.sqlite
**[2.7G]  other.xml
[2.8G]  other.xml.sqlite**
[201M]  primary.xml
[255M]  primary.xml.sqlite
[716M]  other.xml.gz