Magento site is frequently getting CACHE issue and failing to serve CSS, site is getting broken page

Magento site is frequently getting CACHE issue and failing to serve CSS, site is getting broken page.

Once after flush redis cache or restart of redis is bringing site into normal position.

Below cache technologies being integrated for magento web site.

1. Magento: 1.9.1.0
2. Redis: 3.0.5
3. Lesti FPC

Server have two redis instance running with Port No: 6379 and 6380

Site is configured with redis cache for magento backend and full page cache (FPC site cache), Redis’s 6379 instance is configured for both cache setup but redis database are different.

Configurations as below:

backend redis configurations in local.xml

[![<cache>
<backend>Cm_Cache_Backend_Redis</backend>
            <backend_options>
                <server>127.0.0.1</server>
                <port>6380</port>
                <persistent>cache-fpc</persistent>
                <database>1</database>
                <password></password>
                <force_standalone>1</force_standalone>
                <connect_retries>1</connect_retries>
                <lifetimelimit>86400</lifetimelimit>
                <read_timeout>10</read_timeout>
                <compress_data>1</compress_data>
                <compress_tags>1</compress_tags>
                <compress_data>gzip</compress_data>
            </backend_options>

</cache>][1]][1]

FPC site cache redis configurations in fpc.

    <fpc>
            <lifetime>86400</lifetime>
<backend>Cm_Cache_Backend_Redis</backend>
            <backend_options>
                <server>127.0.0.1</server>
                <port>6380</port>
                <persistent>cache-fpc</persistent>
                <database>1</database>
                <password></password>
                <force_standalone>1</force_standalone>
                <connect_retries>1</connect_retries>
                <lifetimelimit>86400</lifetimelimit>
                <read_timeout>10</read_timeout>
                <compress_data>1</compress_data>
                <compress_tags>1</compress_tags>
                <compress_data>gzip</compress_data>
            </backend_options>
</fpc>

Scheduled redis cache clearing cronjob as per this reference URL: http://inchoo.net/magento/using-redis-cache-backend-and-session-storage-in-magento/

30 02 * * *     /usr/local/bin/redis-cli -h localhost -p 6379 flushall
31 02 * * *     /usr/local/bin/redis-cli -h localhost -p 6380 flushall