Caching is a method that improves PDF Share Forms scalability and performance.
Detailed information about caching in SharePoint can be found in the following article: AppFabric and Distributed Cache Service.
When PDF Share Forms Information Worker is installed, it uses default SharePoint caching application - AppFabric Cache.
Although AppFabric is supported by Information Worker, Microsoft has announced the retirement of AppFabric
Official Microsoft Support Lifecycle for Microsoft AppFabric 1.1 for Windows Server has been extended such that Mainstream Support will be provided until 4/11/2017 and Extended Support until 4/12/2022
Therefore, Microsoft recommends using alternative technologies for new applications.
Best replacement application, that Microsoft suggests to use is Microsoft Azure Redis Cache or on premise caching solution Redis, which is open source product. Please see the following Microsoft article that describes Redis and Microsoft Azure Redis Caching: Microsoft AppFabric 1.1 for Windows Server Ends Support
For SharePoint Enterprise we need on premise caching solution. Documentation and details can be found on Redis official site: Redis
In order to update AppFabric to version 1.1m use following link: Cumulative Update 7 for Microsoft AppFabric 1.1 for Windows Server
In order to install and start using Redis, follow these steps:
Step 1. Microsoft Azure Redis Cache can be downloaded by opening this link: Microsoft Azure Redis Cache for Windows. Download .msi file and start the setup
Step 2. Please read the End-User License Agreement and check the accept check box
Step 3. Choose installation destination folder
Check Add the Redis installation folder to the PATH environment variable if you want to run Redis from cmd. Click Next.
Step 4. Specify port to run Redis on. By default it is 6379 but can be changed to any free port
Check Add an exception to the Windows Firewall. Click Next.
Step 5. Specify Maximal Memory limit for Redis Cache
It is used in order to configure Redis to use a specified amount of memory for the data set. Click Next.
Step 6. Start installation
Step 6.1 Installation begins
Step 7. After the installation is complete click Finish
Step 8. Open Central Administration → PDF Share Forms IW → choose Redis or Microsoft Azure Redis and write localhost:<port that was specified on step 4>
Redis is configured and ready to be used with PDF Share Forms Information Worker.