Applying a Time Filter to Session Results

Message Analyzer enables you to filter messages in data viewers that you have opened, such as the Analysis Grid and Chart viewers, based on a configured time window in which you elect to view messages. This feature is called a Time Filter and it is accessible from the Add Filter drop-down list on the Message Analyzer Filtering Toolbar that displays above the analysis surface where data viewers appear when selected. You can configure a Time Filter for Live Trace Session results similar to the way you configure a Time Filter for a Data Retrieval Session with some exceptions, as described in Applying an Input Time Filter to a Data Retrieval Session, which includes employing controls that you can use to define the Start Time and End Time of a time window in which to view messages. However, the scope of these Time Filters is different, as are some label and naming nomenclatures of the user interfaces involved.

The difference in scope of these Time Filters has to do with the context in which they are applied. For example, if you apply a Time Filter to data that you load into Message Analyzer through a Data Retrieval Session, only the messages that fall within the time window that you specify in the time-filter configuration are retrieved. All other messages are filtered out when the data is loaded, which therefore makes such filtered messages unavailable in the chosen Message Analyzer data viewer. Thereafter, the filtered-out messages can be restored only by undoing the Time Filter configuration and reloading the data from the Edit Session dialog. On the other hand, although a Time Filter for a set of trace results applies the same type of time-slot filtering, it does so in the context of an already parsed message collection. This means that the original raw trace data is preserved in the Message Store even if the message display is altered by the way you manipulate the data. As a result, a Time Filter for trace results provides the convenience of enabling you to toggle back and forth between the original trace results and the time-filtered trace results, which can be a benefit to your analytical processes.

Considering Performance vs. Usability Factors for Time Filter Application

You can apply a Time Filter against a set of trace results after it is loaded into Message Analyzer or you can apply an input Time Filter at the moment when you actually import the same data into Message Analyzer. To decide which is best in your circumstances, you might want to consider the tradeoffs between performance and usability, especially when loading data from very large files.

Applying a Time Filter When Retrieving Data
When you apply a Time Filter to a Data Retrieval Session, the amount of data being loaded is reduced to a specified time window, which results in less impact on CPU and memory resources, and therefore demonstrates better performance. However, the resulting data set has all messages removed that are outside the specified time window, which could have an impact on usability and data analysis in terms of message context and other relationships. Moreover, an input Time Filter might obscure conversation contexts in the filtered message collection that you import, whereas a Time Filter applied to a set of trace results does not. To avoid the loss of data in the case of the former, you would need to edit the Data Retrieval Session by setting a new Time Filter window in the New Session dialog and then reload the data. In the case of the latter, Message Analyzer enables you to remove or resize and reapply the Time Filter to the current set of trace results as necessary, making it more convenient to work with the data, given that a data reload is unnecessary.

Also note that for some input file types, Message Analyzer may not be able to determine the start and end times, in which case the Time Filter controls in the New Session dialog for a Data Retrieval Session will be disabled. However, you can always utilize the Time Filter feature after the data displays in your Analysis Session, as needed, regardless of the input file type.

More Information
To learn more about applying a Time Filter when loading data from logs and trace files into Message Analyzer, including the file types for which Message Analyzer can determine start and end times, see Applying an Input Time Filter to a Data Retrieval Session.

Applying a Time Filter to Live Trace Session Results
On the other hand, if you wait to apply a Time Filter to a set of messages that are already displayed in a data viewer such as the Analysis Grid, an applied Time Filter must check the time stamps on each message in the entire collection against the filtering criteria, which can impact performance if there is a very high message volume. However, usability is improved since you can easily restore the entire message set, including conversation contexts, with a single click of the Apply button in the Time Filter panel on the Filtering toolbar after altering the time window as needed, for ease of analysis.

Configuring a Time Filter for a Set of Trace Results

When you are ready to configure a Time Filter for a set of trace results, select the Add Time Filter command that displays when you click the Add Filter drop-down list on the Message Analyzer Filtering Toolbar that appears just above the analysis surface where all data viewers display. This action displays the Time Filter panel that contains Start Time and End Time text boxes that by default display the original time window boundaries of the displayed message collection, along with a set of time slider controls that enable you to adjust the window of time in which you want to view data.

As you change the time window with the slider controls, the time values in the Start Time and End Time text boxes display also change. When you finish adjusting the time slider controls, the corresponding new start and end time values define the selected time window in which you are choosing to view data.

As you set the slider controls, Message Analyzer creates a Filter Expression in the background that will facilitate the time-filtering action. Note that you can manually specify time stamps in the Start Time and End Time text boxes; however, any time stamp that is outside the message collection time boundaries will create an erroneous Time Filter.

Applying a Time Filter

After you set the time window configuration for a Time Filter as previously described, you can apply the filter by clicking the Apply button on the Time Filter panel. Message Analyzer responds by displaying only the messages that fall within the time window you specified. If you want to return to the unfiltered display of original message data, click the Remove button on the Time Filter panel. This action removes the effects of the previously applied Time Filter, but does not alter the time window configuration that you specified. If you want to reapply the Time Filter, you can do so by clicking the Apply button again on the Time Filter panel. You can toggle back and forth between the filtered and unfiltered view configurations as many times as you want, as the time window values that you set for a particular session viewer will persist until you change them.

See Also

Using the Filtering Toolbar