• Virtual Directory Server
• LDAP Proxy
• Federated Identity Suite
• Free LDAP Browser

Caching Solutions

Challenge
While, some vendors will make a big deal of caching, Symlabs believes that in general caching should be avoided as a long term performance or failover strategy. Usually, where caching is required, it is indicative of some other underlying problem in the infrastructure that needs to be resolved. Nonetheless, there are particular cases where caching can be used to temporarily resolve a performance or failure issue.

For instance, it is quite possible that a backend server cannot cope with the amount of traffic that it is handling, resulting in outages or major performance hits within your infrastructure. While the long term solution would be to implement additional replica servers and load-balance requests across them, caching might be used to handle an exceptional traffic spike, or as an interim solution.

Perhaps the best use of a cache is to offset unnecessary traffic generated by poorly designed client applications that may be repeatedly performing the same query many times in a row. In this case, it may not be possible to alter the application, and it may not be justifiable to increase the scale of your architecture for one application.

Whatever the scenario, there may be a time where you need to implement a caching solution to improve performance or to protect against system failures or scheduled downtime, and the solution should be easy to implement.

Solution

Symlabs Virtual Directory Server and LDAP Proxy include various plugins that facilitate the caching of search requests and results, as well as the caching of particular entries. These caching plugins can be configured to control the size of the cache, the number of entries to store, the length of time that they should be stored for and how to handle a situation where once the entries have expired the backend is not available.

Caching can be used in conjunction with Symlabs 'Resolve Dynamic Groups' plugin, which can resolve a dynamic group and present it as a static one. Using the caching plugins in conjunction with this functionality can massivley enhance performance and reduce overhead on your backend servers. As the number of users within a dynamic group grows, the cache will prove to be an effective resource in environments where dynamic groups are frequently used and the application design is such that it struggles to cope with dynamic group functionality.