Chapter 2. Infrastructure planning 33
2.4.3 Web application server
The representative web application solution are the IBM WebSphere, the Red Hat JBoss and
the Oracle WebLogic. These solutions have almost the same I/O pattern with a web server.
Consider the following parameters for GPFS random I/O:
pagepool: The default pagepool parameter size is typically not sufficient for random I/O or
workloads involving a large number of small files. In certain cases, allocating 4 GB, 8 GB
or more memory can improve workload performance.
prefetchPct: This parameter defaults to 20% of pagepool. GPFS uses this value as a
guideline to limit how much pagepool space will be used for prefetch or write-behind
buffers in the case of active sequential streams. The default works well for many
applications. Alternatively, if the workload is mostly sequential (video serving and ingest)
with little caching of small files or random I/O, increase this number up to its 60%
maximum so that each stream can have more buffers available for prefetch and
worker1Threads: This parameter controls the maximum number of concurrent file
operations at any one instant. If there are more requests than that, the excess waits until a
previous request has finished. This attribute is primarily used for random read or write
requests that cannot be pre-fetched, random I/O requests, or small file activity. The default
value is 48. The minimum value is 1. The maximum value of prefetchThreads plus
worker1Threads is 550 on 64-bit kernels.
blocksize: A smaller block size is likely to offer better performance for small file, small
random read and write, and metadata-intensive workloads.
2.4.4 Media contents delivery
This section provides details about media delivery contents in a GPFS cluster environment.
3D animation development infrastructure
How do you design and build this type of system? If you start with no studio and want to
create a full-length feature animation studio, what kind of infrastructure will you need?
Note: This is the pagepool on the GPFS client and not the GPFS server.