Additional Guidance on TIM Sizing

Document ID : KB000010622
Last Modified Date : 14/02/2018
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Introduction:

  This is based on information created by the SWAT organization and should be treated as a guideline only. Professional Services/Pre-Sales should be able to provide additional information if needed.

Environment:
All Supported APM Environments with any type of TIM.
Instructions:

Introduction

These sizing guidelines are for using the TIM on physical hardware (as opposed to a virtual machine).

As a general note, the number of configured transactions, components and parameters, as the quality of the traffic (missing packets) and the type of traffic (xml has a huge impact, monitoring very large bodies etc. will require large disk space for intermediate storage). So all these need to be taken into account.

 

Consideration Points

When considering a TIM, keep the following points in mind when ordering/prepping the hardware. Some of these points would require a prior POC to have taken place, as no possibility would exist to gain the required information without it.

  • CPU Speed: The more MHz, the better. Even though the TIM running on an HP OS is using by default as many workers as there are CPU cores, if there is no real way to do a decent load balancing (due to an application level firewall or a load balancer actively terminating the TCP/IP Session and opening a new one), the CPU MHz will define what throughput the system can handle.
    Note: Usually, using more than 16 TIM Workers starts reducing the overall system performance, so if the system has 24 Cores, adapt the balancer.cnf file to limit the number of workers.
  • Figure 1GB per CPU Core per TIM Worker + 2GB for the OS. 
    + If you add a Ram-Disk for data-exchange between the data-collector and the TIM, add this amount of RAM to it. 
    + If the traffic the TIM has to analyse is of bad quality, packet drops occur etc., the TIM will need more RAM to process the missing packets. Add 1GByte per worker as one will need to increase the capture buffer size and the watchdog configuration accordingly.

An example with bad traffic quality and one with good traffic quality.  

Allocate for

Nr.

Allocated RAM

Bad traffic?

Total

 

Allocate for

Nr

Allocated RAM

No Bad traffic

Total

Operating System

1

2GBytes

N/A

2GBytes

 

Operating System

1

2GBytes

N/A

2GBytes

Active TIM Workers

8

* (1GByte

+1GByte)

=16GBytes

 

Active TIM Workers

8

1Gbytes

N/A

8GBytes

Pkt transition RAM Disk

1

4GBytes

N/A

4GBytes

 

Transition RAM Disk

1

4GBytes

N/A

4GBytes

Overall RAM requirement

 

 

 

22GBytes

 

Overall RAM requirement

 

 

 

14GBytes

  • If you have the possibility to use network cards with Intel Chipsets, do it. Intel chipset based network cards have proven to be more reliable and have larger internal buffers. 
  • In any case, make sure to use network-card which have one chip allocated per port. Dual-Port cards using only one Chip will split the internal buffers among the ports, reducing the amount of data the card can buffer per network feed and at the same increasing the number of interrupt requests the CPU will have to handle to free the network cards buffers.
Additional Information: