Upgrading Memory for WSA S380.

[Viet Bui]

Hi Everyone,

I have bought two new S380 few months ago. but recently they might be increasing the memory usage. the memory usage always at around 60-70%.

I want to upgrade RAM for these appliances but don't know whether they can upgrade or not?

i found that, WSA S370 can upgrade RAM, so I think S380 could be the same, but still not sure.

- here is the link for upgrading RAM for S370:  http://www.cisco.com/c/dam/en/us/td/docs/security/content_security/memory/x70_series_upgrade.pdf

Could you please help me to answer my question.

thanks,

[Philip D'Ath]

I couldn't find much. I found this document that says the S380 has 4 x 4 GB DDR3-1600-MHz RDIMM DRAM.

http://www.cisco.com/c/dam/en/us/td/docs/security/esa/hw/380_680_Series_HW_Install.pdf

You could experiment with getting 4 x 8GB RDIMMS and see how it goes.  This could impact things like swap space as well.

[Viet Bui]

i need to make sure before i buy new RAM. don't wanna loose money :)

[Philip D'Ath]

I get the impression that Cisco sold these as "fixed configuration" without any intention of the RAM being upgraded.

[Viet Bui]

it could be like that, but the older model S370 allowed to upgrade RAM.

here the link: http://www.cisco.com/c/dam/en/us/td/docs/security/content_security/memory/x70_series_upgrade.pdf

[Hrvoje (Harry) Dogan]

Hi guys,

RAM upgrade from 4 gig to 8 gig for x70 units was an exceptional case, because during their lifecycle we added additional features that simply needed more memory. Furthermore, we did a "silent" upgrade of x70 units to ship with 8 gigs of RAM pretty soon after production started, so only initial batches of x70s had 4 gigs of RAM installed. This is why we offered a free of charge upgrade to 8 GB for those initial units.

Adding RAM, while technically possible, would immediately void your warranty. WSAs are delivered as fixed-configuration appliances, and you are not allowed to exchange or upgrade any component yourself.

That said, it is 100% normal to see high memory load on the WSA - it allocates any available memory for caching. So,  the fact that you see higher memory occupancy is just a confirmation that the unit works, and caches content :)

Hope that clarifies it a bit.

[Viet Bui]

Thanks hrdogan  for the reply. it's really helpful.

does this increasing memory usage is related to number of concurrent users.

i've bought licenses for 300 user but just used 20. if my concurrent user up to nearly 300. does this impact? does this increase the memory usage much?

please help me to clarify.

thanks,

[Hrvoje (Harry) Dogan · Accepted solution]

No, there is no impact - WSA uses memory and disk to cache content. Most accessed content is kept in the memory, and less frequently accessed objects are in the disk cache. It is quite normal to see high memory usage, the fact that you have "only" 60-70% means that you have very few users, and don't push much traffic through the box :)

CPU load is a much better indication of potential problems, memory is rarely a bottleneck.

[Viet Bui]

Hi hrdogan   ,

there are two things need your help again about this device.

- when i put S380 into my LAN network, the performance of web surfing decreased around 50%. i think it's too much impact. how can i solve it? what is the main paint point here?

- After i view the caching  information from S380, there are few information about cached contents, Could you please help me to explain more detail about the Cache Hit Rate? what is each propertie mean.

for examp: what is Average in last minute, maximum in last hour (2), what is Max since proxy restart....

thanks,

[Hrvoje (Harry) Dogan]

Hi there,

It's not easy to comment on the surfing performance without additional data - I would recommend that you reach out to your Cisco Systems Engineer or Consulting Systems Engineer for Security for more information. I see that your response times are pretty long, so I would check/verify if network is set up correctly on the WSA - can it access DNS, does it get fast and proper responses (DNS is critical for several functionalities of the appliance), are all engines running and updated with latest signatures, if you are using authentication, is authentication working properly (and fast)... there are unfortunately too many variables to say.

Regarding proxy stats, Cache Hit Rate will show you how many times were objects served from cache. Most objects on the Web today will not be cached, though. It will either be dynamic content, content that is declared as "do not cache" by the server, or HTTPS (for confidentiality reasons, we do not cache objects fetched over HTTPS). Cache Hit Rate stats are per second - so, you should read the report lines as:

"Average cache hits/second in last minute"
"Maximum hits/second in the last hour"
"Average hits/second in the last hour"
"Maximum hits/second since proxy restart"
"Average hits/second since proxy restart"

Again, this goes to show that there's not much activity on the box.

One more thing to mention: WSA is optimised for concurrency; meaning that the way we handle connections and manipulate TCP windows and a bunch of other parameters will make it perform better under multiuser load with many connections being opened and closed simultaneously, but will not be optimal for a single (user) stream of long requests.

Hope that helps.

[Viet Bui]

Thank so much hrdogan  for your answer.