print barcode c# zebra Data collection in Visual C#.NET

Creator Quick Response Code in Visual C#.NET Data collection

collection set is whether its data is cached before being uploaded to the MDW. As we ll discuss shortly, caching collected data before upload reduces the cost of the collection process, particularly for large and/or frequently collected data sets. If the cache directory is not specified, cached data collection sets will use the directory specified in the %TEMP% or %TMP% system variables. For more control over disk usage, specifying a custom directory is recommended, ideally on a disk separate from data/transaction log files. Further, the SQL Agent service account will need read/ write permissions to the specified cache directory. Once you enter these settings, the wizard completes and creates the necessary components to begin collecting and uploading to the selected MDW. Without any further action, the system data collection sets will remain configured with default settings determining the upload frequency, cache method, and data retention period. To gain a deeper understanding of the data collection platform, let s look at the properties of the default data collection sets and how they can be customized.

Once configured for data collection, a SQL Server instance is enabled with three default system collection sets and the ability to define custom sets if required. In both cases, there are a number of important considerations about upload frequencies/ methods and retention periods. All of these properties can be accessed and modified in SQL Server Management Studio under the Management > Data Collection folder by right-clicking on a collection set and choosing Properties.

Each data collection set has its own data collection and upload method, with the two options being Non-cached and Cached. As the name suggests, the cached method collects and caches data locally before uploading to the MDW. In contrast, the noncached method collects and uploads at the same time, using the same schedule. Non-cached mode is typically used for lightweight and/or infrequent collection sets such as Disk Usage. In contrast, both the Query Statistics and Server Activity sets should (and do) use cached mode because their collected content is greater and occurs more frequently. Non-cached mode collects and uploads on the same schedule, which can be specified via the General page of the collection set s Properties window by clicking the Pick or New button. In figure 15.5, the Server Activity collection set is defined with the cached upload method. Earlier in the section (figure 15.4) we covered the initial configuration of the data collection platform, part of which was selecting a cache directory. This directory is used by each data collection set using cached mode. When cached mode is selected, the Uploads page of the collection set s Properties window lets you select or create an upload schedule, as per figure 15.6. The collection schedule is specified using the General page, as shown in figure 15.5, by entering a value in the Collection Frequency (sec) column.

Figure 15.5 The Properties window of each collection set lets you configure the upload mode and schedule as well as the data retention period.

Figure 15.6 The Uploads page of the collection set s Properties window is used to set an upload schedule for a cached collection set.

When a large number of servers are frequently collecting and uploading large collection sets, the collective data volume may overwhelm the centralized MDW server. Cached mode allows each uploading server to collect and upload on a staggered schedule, thereby reducing the impact on the MDW server. For example, one server may upload hourly on the hour, with the next server uploading at 15 minutes past the hour, and so forth.

Once the upload mode and schedules are defined for each collection set, SQL Server Agent jobs are used to execute the collection and upload to the MDW. For a cached mode collection set, two agent jobs will be used: one for the collection and another