XIO Cluster Traffic Test

To external applications, XtremIO appears and behaves like a standard block storage array. However, due to its unique architecture, it takes a fundamentally different approach to internal data organization. Instead of using logical addresses, XtremIO uses data blocks internally to store data. According to the block content, XtremIO decides where exactly to place the data blocks.

In a write operation, any data chunks that are larger than the native block size are broken down into standard blocks when they first enter the storage array. The system calculates a unique fingerprint for each of the incoming data blocks, using a special mathematical algorithm. This unique fingerprint is used for two primary purposes:

• To determine where the data block is placed within the array
• Inline Data Reduction

Because of the way the fingerprinting algorithm works, the ID numbers appear completely random and are evenly distributed over the possible range of fingerprint values. This results in an even distribution of data blocks across the entire cluster and all SSDs within the array. In other words, with XtremIO it is neither necessary to check the space utilization levels on different SSDs, nor to actively manage equal data writes to every SSD. XtremIO inherently provides even distribution of data by placing the blocks based on their unique IDs. To achieve peak performance of any storage array, administrators should constantly keep a check on the read/write operations on the clusters, disks, SSDs of the storage array. The shorter the time taken to perform the read/write operations, the better is the performance of the storage array. In order to improve the performance of the storage array and figure out any processing bottlenecks in the storage array, it is necessary for the administrator to carefully monitor the processing capability of each cluster in the EMC XtremIO with respect to the size of the data blocks. The XIO Cluster Traffic test helps administrators in this regard!

This test reports the I/O processing capability of each cluster with respect to the data block size. For each data block size, this test reports how well the data block is processed, the time taken to process each data block size etc. Using this test, administrators can identify processing bottlenecks and initiate pre-emptive actions.

Target of the test : An EMC XtremIO Storage array

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each cluster:data block on the EMC XtremIO Storage array.

Configurable parameters for the test

Parameter	Description
Test Period	How often should the test be executed.
Host	The IP address of the storage device for which this test is to be configured.
Port	The port number at which the storage array listens. The default is NULL.
XtremIO User and XtremIO Password	Provide the credentials of a user who has read only privileges to access the XtremIO storage array in the XtremIO User and XtremIO Password text boxes.
Confirm Password	Confirm the password by retyping it here.
XMS IP	This parameter is applicable only for EMC XtremIO 4.x. By default, None will be chosen from this list. If the target EMC XtremIO storage array is within a XMS Management Server that is auto-discovered, then the IP or host name of that XMS Management Server will be displayed in this list. Select that particular XMS IP to configure this test. If you wish to monitor an EMC XtremIO Storage Array that is either not an integral part of the auto-discovered XMS Management Server or a brand new EMC XtremIO Storage Array, choose the Other option. This will enable you to add a new XMS Managament Server. To know how to add a new XMS Management Server, refer to Adding a new XMS.
SSL	The eG agent collects performance metrics by invoking Restful APIs on the target Storage array. Typically, the Restful APIs can be invoked through the HTTP or the HTTPS mode. By default, the eG agent invokes the Restful APIs using the HTTPS mode. This is why, the SSL flag is set to Yes by default. If the target storage array is not SSL-enabled, then the Restful APIs can be accessed through the HTTP mode only. In this case, set the SSL flag to No.

Measurements made by the test

Measurement	Description	Measurement Unit	Interpretation
Read bandwidth	Indicates the rate at which data blocks of this size were read from this cluster.	MB/Sec
Write bandwidth	Indicates the rate at which data blocks of this size were written to this cluster.	MB/Sec
Read latency	Indicates the time taken to read data blocks of this size.	msecs	Ideally, this value should be low. A high value could indicate that read/write operations are slowing down for some reason.
Write latency	Indicates the time taken to write data blocks of this size.	msecs
Average latency	Indicates the average time taken to read/write data blocks of this size.	msecs	A value close to 100 indicates that the SSDs in the cluster are running out of space.
Read IOPS	Indicates the rate of read I/.O operations measured for the data blocks of this size during the last measurement period.	IOPS
Write IOPS	Indicates the rate of write I/O operations measured for the data blocks of this size during the last measurement period.	IOPS