# Presentation: 620675

## Ptolemy EVM Simulation

**-evma**
**	****The  configuration focuses on**
- RCN over myrinet, No extra network for RCN traffic. BM is connected to last leg of switch on RU side and RM is connected to last leg on BU side (see fig on next page) with no barrel shifter on BU side.
- Trigger:
**Poisson 12.5 kHz (default), or Gaussian with cut-off**
- BM Messages
**CMSAllocatemessage is to make an event request to BM**
**CMSClearmessage is to send a clear request to BM**
**CMSConfirmmessage is to assign event ID to BU **
- RM Messages
**CMSRCNMessage is to broadcast event IDs to all RUs**

## RCN over Myrinet

## BCN and RCN Traffic

- No packing of BCN messages
**Each BU makes a request of single event id to BM every time. **
- RCN messages packing factor is 2
**The RCN average latency for informing all RUs  is 112 us (Plot attached), almost all of which is non-overlappable. Since subsequent triggers are separated by 80 us on average,  we have to pack at least two RCN messages to keep up. **
- Event fragments
**Lognormal distribution with 16+/-16 kB/RU**

## RCN Over Myrinet

**Conclusion**
**Our results clearly indicates that we can easily accommodate RCN traffic over the same Myrinet network (250MB/s)  which is being used for BCN and BDN. In this way we can avoid an extra network for RCN ( see next slide for RCN latency plot). **

## RCN Latency

## Active Events in EVM

**The plot on next slide shows the total number of active events in EVM without any involvement of  filter nodes. We increment this total in BM on each arriving trigger. These event are assigned to BU’s which make data request to RU’s. As soon as a particular BU builds a complete event, it immediately sends a clear request to BM to clear this event id and clear its resource. The active number total is decremented each time when BM receives a clear event request from any BU.**** **

## Active Events in EVM

## Filter Nodes

**Farm processing time (FPT)**
-  Lognormal distribution, values given per plot
**Each BU emulates 8 filter nodes**
- Average farm processing time should not exceed 40 ms/event
- BU returns an event ID at the end of its FPT (!)
**As soon as BU builds a complete event, it immediately passes that event to filter node and frees it memory. Upon receiving acknowledgement from filter node at the end of FPT, BU then sends a clear message to BM to clear this event. If all filter nodes are already busy processing event, BU puts this event into filter nodes’ queue with least expected time.**

## Active events in EVM, FPT 40 +/- 0ms

**Active events in EVM, FPT 40 +/- 0ms**

******s**

## Active events in EVM, FPT 40+/-20ms

**Active events in EVM, FPT 40+/-20ms**

******s**

**Steady state level increase supposedly due to queuing in filter nodes.**
**Event with large FPT will delay return of all following events sent to that filter node.**
**System will stabilize if FPT average does not exceed 40 ms.**

## Active events in EVM, FPT 40+/-40ms

**Active events in EVM, FPT 40+/-40ms**

******s**

## Active events in EVM, FPT 30+/-30 ms

**Active events in EVM, FPT 30+/-30 ms**

******s**

## RU max. memory usage (FPT 30+/-30 ms)

**RU max. memory usage (FPT 30+/-30 ms)**

******s**

**As long as the BUs  have free resources, this is independent of the FPT (modulo differences in random generator usage).**

## BU max. active events, FPT 30+/-30 ms 

**BU max. active events, FPT 30+/-30 ms**** **

******s**

## BU max. memory usage, FPT 30+/-30 ms

**BU max. memory usage, FPT 30+/-30 ms**

******s**

## Active events in EVM, FPT 30+/-30 ms, Event Fragments 16 +/- 16/sqrt(8) kB/RU

**Active events in EVM, FPT 30+/-30 ms,**** Event Fragments 16 +/- ****16/sqrt(8)**** kB/RU**

******s**