1) my question what is the reason cpu of the going up suddenly & immediately after few coming down?
has mentioned before run ps -aux to determine this, since you know what time its happening that shouldn't be to hard to figure out.
2) what is swap memory?
swap memory - Google Search 3)some r suggesting in these forum,if u increase the firwall-log & master -capacity optimization --increase the 25000 connection to 50000 connection?
pl clarify
More than likely it is traffic causing the cpu to spike. Basically you need to find out what traffic is causing this.
Write a script to run fw tab -t connections -s and email/page you if it reaches a certain value.