eG Monitoring
 

Measures reported by GFireRegionTest

Caches are an abstraction that describe a node in a GemFire distributed system. Application architects can arrange these nodes in peer-to-peer or client/server topologies.

Within each cache, you define data regions. Data regions are analogous to tables in a relational database and manage data in a distributed fashion as name/value pairs. A replicated region stores identical copies of the data on each cache member of a distributed system. A partitioned region spreads the data among cache members. After the system is configured, client applications can access the distributed data in regions without knowledge of the underlying system architecture. You can define listeners to create notifications about when data has changed, and you can define expiration criteria to delete obsolete data in a region.

Within a GemFire distributed system, you can define distributed regions and non-distributed regions, and you can define regions whose data is spread across the distributed system, and regions whose data is entirely contained in a single member.

Following are the different types of regions that are available for a GemFire Distributed System:

  • Partitioned: Data is divided into buckets across the members that define the region. For high availability, configure redundant copies so each bucket is stored in multiple members with one member holding the primary.

  • Replicated (distributed): Holds all data from the distributed region. The data from the distributed region is copied into the member replica region. Can be mixed with non-replication, with some members holding replicas and some holding non-replicas.

  • Distributed non-replicated: Data is spread across the members that define the region. Each member holds only the data it has expressed interest in. Can be mixed with replication, with some members holding replicas and some holding non-replicas.

  • Non-distributed (local): The region is visible only to the defining member.

If the regions are not updated frequently or if the regions store outdated data, users accessing the data through those regions may be exposed to obsolete data. Therefore, it is important to monitor the regions that store the data in the GemFire Distributed Cache round the clock! The GFireRegionTest test helps administrators in this regard!

This test auto-discovers the regions of the GemFire Distributed syem and reports whether the gateway through which data is sent from each region is enabled, the number of cache members associated with each region, captures the bucket count and rate at which data is added to each region, and measures the level of disk I/O activity on each region, so that administrators are notified of region related problems well before they impact the entire distributed system.

Outputs of the test : One set of results for each Cache Member:Region of the target GemFire server being monitored.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Total_members Indicates the total number of cache members associated with this region. Number  
Average_reads Indicates the average number of read requests received by this region per second. Reads/sec  
Average_writes Indicates the average number of write requests received by this region per second. Writes/sec  
Bucket_count Indicates the total number of data buckets associated with this region of this region. Number Geode automatically determines the physical location of data in the members that host a partitioned region’s data. Geode breaks partitioned region data into units of storage known as buckets and stores each bucket in a region host member. Buckets are distributed in accordance to the member’s region attribute settings.
Bucket_size Indicates the number of data buckets associated with this region to which data was put. Number When an entry is created, it is assigned to a bucket. Keys are grouped together in a bucket and always remain there. If the configuration allows, the buckets may be moved between members to balance the load.
Create_rates Indicates the rate at which data was added to this region. Creates/sec  
Destroys_rate Indicates the rate at which object entry was destroyed from this region. Destroys/sec  
Disk_read_IOPS Indicates the rate at which data was read from the disk associated with this region. Reads/sec Comparing the value of these measures across the regions helps administrators identify the region with the maximum disk read IOPS and disk write IOPS.
Disk_write_IOPS Indicates the rate at which data was written to the disk associated with this region. Writes/sec
Disk_IOPS Indicates the rate at which I/O operations were performed on the disk associated with this region. IOPS  
Disk_usage Indicates the amount of data utilized by the disk associated with this region. MB  
Gets_rate Indicates the rate at which get operations were successful on this region. Gets/sec  
Put_all_rates Indicates the rate at which a map was added or replaced on this region as a result of a local operation. Puts/sec  
Puts_rate Indicates the rate at which data was added or replaced on this region. Puts/sec  
Is_gateway_enabled Indicates whether/not this region sends data through a gateway.   The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure Value Numeric Value
Yes 1
No 0

Note:

By default, this measure reports the Measure Values listed in the table above to indicate whether/not this region sends data through a gateway. The graph of this measure however, represents the status of a server using the numeric equivalents only - 0 or 1.