The HVR hub gathers all information about the jobs it manages. In this section you will explore various ways to monitor data replication activity.
The term Topology is used to indicate an overview of all data replication flows managed by the hub. In a single overview it shows the direction of the data flows, an indication of data volumes, a relative indication of latency, as well as whether jobs are running. The chart is interactive to retrieve more information such as actual current latency and volume information.
1. To get to the Topology, navigate to the node Scheduler in the tree.
2. Pull up the context menu and select Topology.
3. The Topology is displayed in a browser window, which at present can only be shown on the machine running the HVR GUI.
4. Inspect this chart carefully, and close the browser when you are done.
1. Use the LEGEND drop-down on the top right to get a feel for the information displayed on the screen.
2. The settings cog to the right of LEGEND can be used to change some of the information displayed in the chart. Note that, at present, these settings reset when you close the browser and return to the Topology.
3. Click on the lines, and then the arrows to get numerical data from the data flow.
4. In the box on the bottom left that shows the high-level status for your hub, click the mins button to get aggregate statistics updated every minute.
As data flows between source(s) and target(s), HVR keeps detailed logs. Information is then harvested from these logs to publish historical metrics as time-series statistics about the replication flows. The time series use fixed intervals, either minute, 10 minute, hourly or daily intervals, with metrics aggregated to these time intervals (such as total number of changes, or minimal/maximum latency for the interval, etc.).
1. To access Statistics, in the HVR GUI, navigate to the Scheduler node right click to bring up the context menu and select Statistics.
2. Like the Topology view, Statistics are shown in a browser. In fact, using the bar on the left you can switch between Topology and Statistics (and Events, which you will explore later).
Note that the Statistics have a granularity defaulting to hourly with a default window of seven days.
3. Since replication just started on this hub, and to show more detail, use the drop-down on the top right to switch the granularity to minute.
4. To zoom into the chart, either use the time selector, or hover the pointer over one of the charts until a + (plus) sign appears.
5. Horizontally select the portion of the chart you want to zoom into.
By default, HVR shows the most commonly accessed metrics. (i.e. Latency, Captured Changes Counts, and Integrated Changes broken down by Table/Channel.)
6. Take some time to inspect the statistics, and explore what is available:
• More metrics/statistics are available under the + (plus) button below the Time Selector on the right.
• Reported statistics can be broken down differently.
7. Select or de-select statistics to focus on others, or to have HVR automatically adjust the scale so you have access to more details
8. Hover the pointer over the charts to see a pop-up with the detailed values across all visible charts.
9. Close the browser window when you are done exploring the statistics.
HVR is designed to automatically recover from interruptions to data replication and will always resume where it left off. As a result, once configured, HVR can be left alone to manage the replication and periodically you may access HVR to look at the Topology chart or inspect Statistics.
However, there can be scenarios in which replication stops and cannot be resumed without intervention. Examples that could cause replication to fail are: the network became unavailable for an extended period of time, a system crashed due to a faulty part, or a bug in software (either HVR’s or the technologies with which HVR integrates).
Many organizations have Service Level Agreements (SLAs) on data replication and administrators would want to be notified when there are major issues that may result in SLAs getting failed.