Applying Quick Filters
Message Analyzer enables you to filter messages in data viewers that you have opened, such as the Analysis Grid and Protocol Dashboard viewers, based on a configured time window in which you elect to view messages. This feature is called a Quick Filter and it is accessible from the global Message Analyzer Session menu. You can configure a Quick Filter similar to the way you configure a Time Filter in a Data Retrieval Session, as described in Applying a Time Filter to a Data Retrieval Session, which includes employing the Use Start Filter and Use End Filter features. However, the usage context or scope of these time filters is different.
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 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 and reloading the data from the Edit Session dialog. On the other hand, although a Quick Filter applies the same type of time-slot filtering to a trace or other message collection, 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 data manipulation with a filter. As a result, a Quick Filter 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.
When you are thinking about using a Time Filter versus a Quick Filter, for example with one or more log files, you might want to consider the tradeoffs between performance and usability — especially when loading data from very large files. For example, 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 relationships. For example, a Time Filter might destroy conversation contexts in the filtered message collection, whereas a Quick Filter does not. On the other hand, when you apply a Quick Filter to messages that are displayed in the Analysis Grid viewer, the filter must verify the time stamps on each message in the entire collection, 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 after filtering, for ease of analysis.
When you are ready to configure a Quick Filter, click the Edit command in the Quick Filter submenu of the global Session menu to display the Quick Filtering configuration dialog. The dialog enables you to select the Data Source providers used in the trace; it also specifies the Start Time and End Time of the message collection time boundaries and these values are constant even if you make time window adjustments. These constant boundaries are also specified in Start Time and End Time read-only text boxes in the Time Filter pane of the Quick Filtering dialog. The dialog also contains time window-slider controls that enable you to specify a time slot in which to view data. As you change the time window with these controls, the text box below the Use Start Filter check box displays the start time and the text box below the Use End Filter check box displays the end time in the Time Filter pane of the dialog. The corresponding new start and end time values define the selected time window in which you are choosing to view data. The Quick Filtering dialog also provides an estimation of the number of Filtered Messages that will be retrieved in whatever time window you specify.
The Start Time and End Time values that display in the Time Filter pane of the Quick Filtering dialog might not match the Start Time and End Time values that display for the Time Filter boundaries in a Data Retrieval Session configuration for certain input file types. This occurs because Message Analyzer only provides an estimate of time values in certain cases, as described in Applying a Time Filter to a Data Retrieval Session.
As you set the slider controls, a read-only text box in the Filter pane of the dialog displays the Filter Expression that will facilitate the time filtering action, which consists of Timestamp properties that are set to selected Start Time and End Time values. If you select the Use Start Filter and Use End Filter check boxes, the time boundary text box becomes writeable so that you can specify time values in a format that is suitable for the displayed data. Thereafter, as you adjust the time slider controls, the changing time window boundary values match the time stamp format of the displayed data. This feature accommodates for message data that may have time stamps in a format that Message Analyzer cannot adequately determine.
After you set the time window configuration in the Quick Filtering dialog, you can apply the filter by clicking the Apply button in the dialog. 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, you can select the Remove command from the Quick Filter submenu in the global Session menu. If you want to apply the filter again, you can do so by selecting the Apply command from the Quick Filter submenu. You can toggle back and forth between the filtered and unfiltered view configurations as many times as you want, as the values for the last time window that you set for a particular session viewer will persist until you change them.
As you alternately apply and remove a Quick Filter configuration, you can observe the activation of session progress indicators in the Session Explorer Tool Window.