MoreVRP is a database performance monitoring and acceleration tool, and offers DBAs the capability to have real-time monitoring and resource management and control.

1. White Paper
MoreVRP for EMC Greenplum
Performance monitoring and acceleration for Greenplum DCA
Abstract
“MoreVRP for EMC Greenplum” from More IT Resources is the perfect complement to
the EMC Data Computing Appliance (DCA). MoreVRP is a database performance
monitoring and acceleration tool, and offers DBAs the capability to have real-time
monitoring and resource management and control. In addition, the Business
Intelligence historical analysis, with which DBAs can perform drill downs and utilize
the Playback feature, allowing the DBA a frame by frame historical look of any time
frame, for use in pinpointing performance bottlenecks in the database. These
features from MoreVRP are indispensible everyday tool that can help DBAs perform
their duties.
June 2012

2. Copyright © 2012 EMC Corporation. All Rights Reserved.
EMC believes the information in this publication is accurate as
of its publication date. The information is subject to change
without notice.
The information in this publication is provided “as is.” EMC
Corporation makes no representations or warranties of any kind
with respect to the information in this publication, and
specifically disclaims implied warranties of merchantability or
fitness for a particular purpose.
Use, copying, and distribution of any EMC software described in
this publication requires an applicable software license.
For the most up-to-date listing of EMC product names, see EMC
Corporation Trademarks on EMC.com. All trademarks used
herein are the property of their respective owners.
Part Number h10759
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3. Table of Contents
summary................................................................................................
..................................................................................................
Executive summary.................................................................................................. 4
Audience ............................................................................................................................ 4
Glossary ............................................................................................................................. 4
................................................................
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Using MoreVRP with Greenplum DCA ........................................................................ 5
Greenplum DCA .................................................................................................................. 5
MoreVRP ............................................................................................................................ 6
Real-time Monitoring ...................................................................................................... 6
Performance Acceleration............................................................................................... 8
Performance Analytics .................................................................................................... 9
MoreVRP Requirements ......................................................................................... 11
Requirements ................................................................
.........................................................
Setup and Configuration with DCA/GPDB ............................................................... 11
...............................................................
Testing with DCA .......................................................................................................... 12
Testing with Single-Node Greenplum Databases .......................................................... 14
Testing with Multiple DCAs ........................................................................................... 14
Conclusion ............................................................................................................ 14
............................................................................................................
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References ............................................................................................................ 15
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4. Executive summary
“MoreVRP for EMC Greenplum” from More IT Resources is the perfect complement to
the Greenplum Database and the EMC Data Computing Appliance (DCA). MoreVRP is a
database performance monitoring and acceleration tool that offers DBAs the
capability to have real-time monitoring and resource management and control.
In addition, MoreVRP comes with a Business Intelligence historical analysis feature,
with which the DBA can do performance drill downs and also has a Playback feature,
allowing the DBA a frame by frame historical look of any time period for use in
pinpointing performance bottlenecks in the database. These features from MoreVRP
are an indispensible, everyday tool that can help DBAs perform their duties, giving
their users the best quality of Service (QoS) and service level agreement (SLA),
maximizing workload concurrency by allowing more transactions to be executed
concurrently.
MoreVRP helps system administrators improve their DCA system performance,
availability and stability, ensuring maximum resource utilization. MoreVRP also
reduces possible downtime due to hung processes, runaway processes, ultimately
improving the total cost of ownership.
Audience
This paper is intended for EMC field personnel and customers intending to use
MoreVRP to monitor and control the performance of their Greenplum databases and
Greenplum Data Computing Appliances.
Glossary
The table below contains some frequently used abbreviations and terms used in
conjunction with Greenplum:
BI Business intelligence
DBA Database Administrator
DCA Data Computing Appliance
DIA Data Integration Accelerator
EDW Enterprise Data Warehouse
ETL Extract, Transform and Load
LAN Local Area Network
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5. NIC Network Interface Card
Using MoreVRP with Greenplum DCA
Greenplum DBAs want to provide their users with consistent quality of service and
high performance, ensuring that all database processes receive optimal CPU and IO
resources. To monitor and manually control all transactions in a database is a full
time job without performance monitoring and management software.
MoreVRP helps system administrators improve their Greenplum database and DCA
system performance, availability, and stability, ensuring maximum resource
utilization and reducing possible downtime due to hung processes, runaway
processes, ultimately improving the quality of service.
MoreVRP also has an extremely small overhead. The software employs agents that
run on each server to be monitored. For the Greenplum database and the DCA this
includes the master server, the standby master, and all segment servers in the
cluster. Each agent utilizes about 1% of a single CPU resource in testing on a DCA,
and thus is unobtrusive to normal database operations.
MoreVRP collects performance statistics and stores them in a smart repository. This
can be a small database in the MoreVRP server, in the Greenplum database itself, or
in a separate database in the DCA. The collected statistics are useful in performing
playback and can also be used in drill-down situations to find bottlenecks in the
database.
MoreVRP comes with many modules and tools to help DBAs manage their databases.
It understands the Greenplum and DCA architecture, and its analytical tools are tuned
to help DBAs identify skews that are caused by uneven distribution, hot nodes and
segments.
Greenplum DCA
EMC’s Greenplum Data Computing Appliance (DCA) brings the power of a massively
parallel processing (MPP) architecture while delivering the fastest data-loading
capacity and the best price / performance ratio in the industry,without the complexity
and constraints of proprietary hardware. The DCA is a purpose-built, highly scalable,
parallel EDW appliance that integrates database, compute, storage, and networking
into an enterprise-class, easy to implement system.
The DCA is a self-contained data analytics solution that integrates all the database
software, servers, and switches that are required to perform enterprise-scale data
analytics workloads. The DCA is delivered in its own rack, ready for immediate data-
loading.
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6. The components of the DCA are:
• Greenplum Database (GPDB) — this is an MPP database server, based on
PostgreSQL open-source technology. The GPDB is explicitly designed to support
business intelligence (BI) applications and large, multi-terabyte data warehouses.
• Master Servers — the servers that run the master database, responsible for the
automatic parallelization of queries. This is the entry point to the GPDB. There are
two servers — a master and a standby server — to cover for
failover situations.
• Segment Servers — the servers that run the segment instances
and perform the real work of processing and analyzing the data.
Segment servers come in modules of four servers, and can have
up to 16 servers in a DCA cabinet. Up to 12 full cabinets can be
supported in a single cluster.
• Interconnect BUS — The Interconnect Bus provides high-speed
communication between the master and segment servers. It
consists of two 10 Gb switches to communicate requests from
the master to the segment servers, between Segment servers
themselves, and to provide high-speed access to the segment
servers for quick parallel loading of data across all segment
servers. Data moves between the segment servers and the
master servers over the interconnect bus.
• Administrator Switch — the Admin Switch provides the
management interface between the servers and additional racks.
To ensure all these components work in concert at the maximum efficiency requires a
good monitoring and resource provisioning system. This is where MoreVRP comes in.
MoreVRP
A good database administrator worth his salt will have every statistics and operations
of his database at his finger tips. This is easily accomplished with the help of a
performance monitoring tool like MoreVRP. MoreVRP for Greenplum Database has
three main functions:
• Real-time monitoring
• Performance and SLA acceleration
• Powerful performance analytics
Real-
Real-time Monitoring
On starting MoreVRP, the entry screen is the Dashboard. The Dashboard shows real-
time statistics and the current status of active database transactions. If transactions
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7. have sub-threads, the transaction can be opened to see the sub-threads and their
statistics.
Figure 1 MoreVRP Dashboard
To the right side of the Dashboard are color-coded gauges that show the health status of
the machine (DCA) or the system being monitored. IO usage and CPU statistics are also
displayed in graph format. Using the dashboard and gauges, DBAs can monitor active
transactions as shown in the figure below
Figure 2 Database transactions
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8. Figure 2 shows an example of the Dashboard and database transaction threads
running in the DCA. Information about each thread, including process ID, database
used, user name, “Control”, whether the process is currently being controlled by
moreVRP or not, the CPU percentage usage of each process, the number of read and
write I/Os being achieved by each process, the SQL command used, and the start
time of the process, can be queried.
To the left side of each process line, there is a right facing triangle. If the process can
be detailed by displaying its sub-processes, one such triangle will be displayed. By
clicking on the triangle, you will open up a display of lines of sub-processes. You can
click on each sub-process line to define the percentage CPU or I/O activities you want
each sub-process to achieve, and MoreVRP will make sure that these limits are
enforced.
Performance Acceleration
From the list of transactions being monitored in the dashboard, transactions can be
accessed and run real-time performance control can be managed. MoreVRP can be
instructed to allocate a specificed amount of CPU usage, or IO per second on certain
transactions, or threads. This allows MoreVRP to redirect CPU and IO resources freed-
up by the restrictions to that thread to the resource pools. The remaining
transactions are able to perform better and complete their work quicker. This
capability can be used to proactively allocate resources such as IO and CPU resources
in your system to some transactions, and free up the logjam in your system’s
workload.
Over time, as the system workload becomes familar and transactions that cause slow
system performance are identified, rules can be created to anticipate these situations
and automatically restrict resources to the transactions that may cause problems,
and free up those that do not.
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9. Performance Analytics
Figure 3 - Top users
As you monitor the database performance, MoreVRP collects the information and
stores them in a repository. Using the database repository of all the monitored
threads and transactions, MoreVRP can extract statistical information and perform
Business Intelligence and Analytics using these data:
The Performance BI feature can list out transactions and user names, and sort out the
top users of using the most resources, or the most number of transactions.
Figure 4 Monitor SQL transactions
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10. If a DBA is interested in finding out what SQL statements the users are running, the
Performance BI feature can also list that, and can sort it by resources used.
MoreVRP has many other useful features, including:
• The ability to run the Playback module to watch historical events one frame at
a time. This is useful in debugging past events, and pinpointing a runaway
process or an offending SQL statement, applying remedies to the problems so
that they will not happen again.
• A powerful rules engine allows a DBA to set up detailed rules that will be
called up, and applied in specific circumstances. This allows the user to
automatically control processes that reach a pre-defined threshold, preventing
unwanted resource hogs or runaway processes.
• The ability to create customer performance reports of usage and performance
bottlenecks. These reports can pinpoint the users with the most usages, and
time and day of that are the business periods.
• Using the Variance module, DBAs can compare performance differences
between databases, segments, time and spot anomalies. Using this report
execution plans that have changed and are causing problems in the system
can be identified. For customers upgrading their DCA, or their Greenplum
Database from one release to another, the Variance report can be used to
verify performance differences.
• The Chargeback module is useful for IT department to track tenant activities,
and can monetize system usage, to be used to cross-charge the users for
system usage.
• Standard performance graphs are available to track SQL usage, CPU and IO
utilization, and allow the DBA to drill down to a single query execution. These
graphs give the DBA a good idea of what goes on in the database at any time.
• Utilization charts can be used to track top users — users allocated the most
resources. Use this to pinpoint the performance problems in your DCA, as well
as system hogs that are getting the most of your resources.
Figure 5 - performance variance report
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11. MoreVRP Requirements
The MoreVRP GUI console is a Java client that can run on any Windows platform, from
Windows XP to Windows 7. Ideally, it requires the Windows client to have the
following hardware:
• 8 logical cores or better processing power for a full rack DCA
• 8 GB of RAM
• 50 GB for disk space for database repository to store about 3 months of activities,
and
• At least one 100 Gb/s NIC. A GigE NIC is preferred.
The software requirement for MoreVRP is very modest. The MoreVRP client runs on
Firefox 3.11, Chrome 2.0, or Internet Explorer 7 and higher versions of browsers. For
Java JRE, it requires version 6 update 16 and higher, and it also requires Adobe Flash
version 10 and higher versions.
For testing, a physical server with little more than the required hardware features was
obtained and all required software was installed
Setup and Configuration with DCA/GPDB
The following sections describe three hardware setup configurations for the test server. The test
plan included:
1. Monitoring and controlling a full rack DCA.
2. Monitoring and controlling a single-node Greenplum Database.
3. As a corollary of #1, once we finished testing with a full rack DCA, we want to extend the
monitoring to a second full rack DCA.
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12. Testing with DCA
Figure 6 - Interconnect Network
In order to monitor the segment servers in a DCA, connectivity to the interconnect
switch of the DCA is needed. This requires the test server to be dual-homed, with one
NIC port connected to the management LAN, and another NIC port connected to the
Allied Telesis (Administrator) switch (figure 7). The AT switch has connections to the
Brocade 8000 (interconnect) switch into which all the segment servers are connected,
and thus allows connections from the test server to the segment servers.
Figure 6 above shows the DCA interconnect network. The MoreVRP server ideally
needs to have connectivity to either Interconnect switches, or at least one of them, to
be on the interconnect network. Connecting to the AT switch creates an indirect route
to the segment servers.
A random, unused IP address from the 172.28.8.x subnet was selected and assigned
to the test server. From there, the only thing that needed to be done is to update the
/etc/hosts file in each segment server, to include the test server’s name and IP
address.
That done, each segment server was pinged to verify connectivity from the test server.
Using the MoreVRP GUI, the master server and all the segment servers were added
into the MoreVRP console, and were ready to start monitoring the DCA.
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13. Figure 7 - Allied Telesis switch inside the DCA
Figure 8 - Dual homed server
Figure 8 shows the MoreVRP test server with a NIC with dual ports. One port was
connected to the Allied Telesis switch. The second port was connected to the LAN
switch.
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14. Testing with Single-Node Greenplum Databases
Single-
For testing with a single-node (SNE) Greenplum Database (GPDB), MoreVRP can be
installed on a VM Windows server. Network connectivity between the VM server and
the Single-node GP database server is required. As long as each server can ping each
other, MoreVRP will work. Since there is no segment server in a single-node GPDB,
only the top level process threads in the dashboard can be listed - you will not be
able to drill down to the sub-threads as you would in a DCA. Other than that, DBAs
can have most of the other features running in this setup.
As far as control is concerned, if multiple processes are running in the SNE, the
performance acceleration feature can still be used, including apportioning the I/O
and CPU resources between the processes, without going down to the sub-processes.
Testing with Multiple DCAs
If DBAs need to connect to more than one DCA, the current solution is to have more
than one MoreVRP server, one for each DCA. Another NIC should not be added to the
same MoreVRP server and connect the additional NIC to the second DCA. This does
not work due to the same node names being used by each DCA, as well as the same
IP addresses used in the segment servers. At the time of publication, there is no
official solution for this, but MoreVRP notified that they now support the functionality
using IPv6 configuration, or IPv4 configuration with separate subnets. MoreVRP
suggested the following solutions:
1. The (Brocade 8000) interconnect switch supports IPV6, and so does the MoreVRP
network drivers. If you can connect the MoreVRP server to both DCAs and connect
using unique IPV6 address across the multiple DCA cabinets, this will allow
MoreVRP to monitor all the connected segment and master servers.
2. For a solution without using IPV6, you will need to define different subnets at the
MoreVRP server for both interfaces. It will be the same IP addresses for the intra-
cabinet servers, but on different subnets for each DCA.
Conclusion
MoreVRP for EMC Greenplum is a good complement to the DCA software stack. DBAs
can use it to monitor and control the database performance, and use it as an
analytical tool to pinpoint bottleneck in the database.
To use MoreVRP with the DCA, you will need to have a dual-homed server with one
connection into the interconnect switch of the DCA. For single-node databases, this
requirement is not necessary.
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15. Using the many tools and features that come with MoreVRP, the DCA system
administrator can ensure that the workload in the DCAs can run in their maximum
performance capability.
References
The following are some useful reference sources for this topic:
1. Greenplum® Database 4.2 Administrator Guide P/N: 300-013-163 Rev:
A03.
http://powerlink.emc.com/km/live1/en_US/Offering_Technical/Technical_Document
ation/300-013-163.pdf
2. Datasheet: MoreVRP for EMC2 Greenplum.
http://www.morevrp.com/images/documents/MoreVRP_for_EMC_Greenplum.pdf
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