Filtering Imported Data
Prior to loading data into Message Analyzer from a Browse Session, you can configure a Selection Filter to “select” specific data from the import configuration to narrow the data retrieval scope, reduce the volume of messages that you load, and therefore improve performance. You can also apply a Time Filter to the import configuration prior to loading data from log files, to reduce the scope of the imported messages to a specific window of time. These filtering features have a significant impact on processing time and performance improvements.
After using the Add Files command in your Browse Session to create a list of files that contain the data you want to import, feasibly from multiple disparate data sources, you can also apply filtering through file selection to create unique message collections. To do this, simply select specific files from among the files that are marked for importing in the Import files list to create a subset of messages that you want to focus on. You can then specify a data viewer in which to present the imported data and the import process is silently invoked in the background.
For example, you might have multiple log files containing data that was collected over a period of time from different sources, for example, from a client and server. You might be interested in isolating the source of a TCP connection issue that involved lost TCP segments but it is unclear which machine was dropping packets. You could import sets of log files from the same time period, possibly while drilling down to a specific window of time with the use of a Time Filter, to select data that was collected on both client and server computers in a specified time window. When viewing results in an Analysis Session, the data from each set is presented as a single unified message collection. You might also configure a Time Shift if the data sets need to be synchronized, as described in Setting Time Shifts.
Using a Selection Filter
You can specify a Selection Filter for your Browse Session by either writing your own Filter Expression or choosing a predefined Filter Expression from the Selection Filter Library. This centralized library contains the same predefined Filter Expressions that you will find in the Trace Filter Library and View Filter Library, in the Message Analyzer Trace Session configuration interface and View Filter group on the Ribbon of the Message Analyzer Home tab, respectively.
If you want to specify a predefined Filter Expression from the centralized user Library for a data import, you should first review the filter functionalities that are described in Filtering Trace Results and then apply an appropriate Selection Filter. If you intend to create your own Filter Expression, see the appropriate topic below for more information about how to write one. After you write a Filter Expression or modify a predefined expression that you want to use as a Selection Filter, you can optionally click the Verify icon to validate that the expression properly compiles. If the Filter Expression does not compile, you will be unable to load data through a Browse Session or capture data through a live Trace Session, respectively, until you either correct the Filter Expression or delete it entirely. If you have an expression that does not compile, Message Analyzer displays a Compile query Error message.