-print-stats

C – Troubleshooting InfiniPath MPI Troubleshooting

Q

C.8.13

MPI Stats

Using the -print-statsoption to mpirun will result in a listing to stderr of various

MPI statistics. Here is example output for theoption when used with an 8-rank run of the HPCC benchmark.

MPIRUN:

MPI Statistics Summary

(min, max, median @ rank)

 

 

MPIRUN:

Messages sent

 

 

 

 

MPIRUN:

Eager count

(min=652.54K @ 0, max=653.39K @ 7, med= 653.15K)

MPIRUN:

Eager aggregate bytes

(min= 2.08G @ 0, max= 2.08G @ 2, med=

2.08G)

MPIRUN:

Rendezvous count

(None)

 

 

 

MPIRUN:

Rendezvous agg. bytes

(None)

 

 

 

MPIRUN:

 

 

 

 

 

MPIRUN:

Messages received

 

 

 

 

MPIRUN:

Expected count

(min=590.48K @ 2, max=624.90K @ 6, med= 619.01K)

MPIRUN:

Expected aggregate bytes

(min= 2.03G @ 2, max= 2.04G @ 1, med=

2.04G)

MPIRUN:

Unexpected count

(min= 27.89K @ 6, max= 62.69K @ 2, med=

39.20K)

MPIRUN:

Unexpected agg. bytes

(min= 44.57M @ 1, max= 57.95M @ 2, med=

48.04M)

MPIRUN:

Unexpected count %

(min=

4% @ 6, max=

9% @ 2, med=

6%)

Message statistics are available for transmitted and received messages. In all cases, the MPI rank number responsible for a minimum or maximum value is reported with the relevant value. For application runs of at least 3 ranks, a median is also available.

Since transmitted messages employ either an Eager or a Rendezvous protocol, results are available relative to both message count and aggregated bytes. Message count represents the amount of messages transmitted by each protocol on a per-rank basis. Aggregated amounts of message bytes indicate the total amount of data that was moved on each rank by a particular protocol.

On the receive side, messages are split into either expected or unexpected messages. Unexpected messages cause the MPI implementation to buffer the transmitted data until the receiver is able to produce a matching MPI receive buffer. Expected messages refer to the inverse case, which should be the common case in most MPI applications. An additional metric, Unexpected count %, representing the proportion of unexpected messages in relation to the total number of messages received is also shown because of the notable effect unexpected messages have on performance.

For more precise information, users are encouraged to make use of MPI profilers such as mpiP. For more information on mpiP, see:

http://www.llnl.gov/CASC/mpip/

For reference on the HPCC benchmark, see:

http://icl.cs.utk.edu/hpcc/

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IB6054601-00 D

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Q-Logic IB6054601-00 D manual MPI Stats
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IB6054601-00 D specifications

The Q-Logic IB6054601-00 D is a high-performance InfiniBand adapter card designed for data centers and enterprise applications requiring robust connectivity and low-latency communication. This adapter is part of QLogic's extensive portfolio of networking solutions, catering to the needs of high-performance computing (HPC), cloud computing, and virtualization environments.

One of the standout features of the IB6054601-00 D is its capability to support data transfer rates of up to 56 Gbps. This makes it ideal for applications demanding large bandwidth and quick data processing. The adapter is optimized for RDMA (Remote Direct Memory Access) technology, which allows data to be transferred directly between the memory of different computers without involving the CPU. This reduces latency and CPU overhead, leading to enhanced overall system performance.

The architecture of the IB6054601-00 D includes support for a dual-port design, which offers increased bandwidth, redundancy, and fault tolerance. This dual-port configuration is especially advantageous for environments that require high availability and reliability, such as financial services and mission-critical applications.

The adapter utilizes advanced error detection and correction mechanisms, ensuring that data integrity is maintained during transmission. With features like adaptive routing and congestion management, the IB6054601-00 D is capable of optimizing the handling of data flows, thereby enhancing performance even under heavy loads.

In terms of compatibility, the Q-Logic IB6054601-00 D supports a wide range of operating systems and virtualization technologies, making it easy to integrate into diverse IT environments. It also includes drivers and software packages that facilitate seamless deployment and management.

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Overall, the Q-Logic IB6054601-00 D stands out for its high throughput, low latency, and reliability. Its combination of advanced features and technologies positions it as an excellent choice for organizations looking to enhance their data center performance and maximize the efficiency of their network infrastructure. With the growing demands for faster and more efficient data transfer, solutions like the IB6054601-00 D are essential in meeting the evolving needs of modern enterprises.
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