Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.
- Create BookmarkCreate Bookmark
- Create Note or TagCreate Note or Tag
- DownloadDownload
- PrintPrint
Chapter 3. ESA Email Pipeline > Work Queue and Filtering Engines
Work Queue and Filtering Engines
The second major stage of the email pipeline is organized into what’s called the ESA work queue. This section is shown in Figure 3-4.
Figure 3-4. Second Portion of the Email Pipeline: the Work Queue
The processing steps taken on a given message in the work queue is mostly configured through Incoming Mail Policies and Outgoing Mail Policies in the Mail Policies menu of the WUI.
Work Queue Overview
The work queue is the place where, not surprisingly, most of the work on the appliance is done. All the custom filtering and security filtering is done here. What’s not so apparent is that, at this point, the ESA is also moving to multiprocessing to take advantage of modern multicore CPUs. The individual filtering engines run in their own process, and multiple instances are run to take advantage of the hardware.
