# description of simulation.log
**URL:** https://community.gatling.io/t/description-of-simulation-log/237
**Category:** Gatling (Open-Source)
**Created:** [January 16, 2013, 9:42pm UTC](https://community.gatling.io/t/description-of-simulation-log/237 "2013-01-16T21:42:40Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Boba\_Jett](https://community.gatling.io/u/Boba_Jett)
#### Post date: [January 16, 2013, 9:42pm UTC](https://community.gatling.io/t/description-of-simulation-log/237/1 "2013-01-16T21:42:40Z")
I couldn’t find any description on the gatling site for the format of the simulation.log?
Specifically what do the 4 timestamps mean?
ACTION Scenario Name 1 request\_1 1358286500405 1358286500405 1358286501515 1358286501710 OK
thanks.
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### Author:  [@Excilys](https://community.gatling.io/u/Excilys)
#### Post date: [January 16, 2013, 9:48pm UTC](https://community.gatling.io/t/description-of-simulation-log/237/2 "2013-01-16T21:48:33Z")
requestStart (first byte sent), requestEnd (last byte sent), responseStart (first byte received), responseEnd (last bytes received)
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### Author:  [@Shawna](https://community.gatling.io/u/Shawna)
#### Post date: [July 8, 2013, 5:56pm UTC](https://community.gatling.io/t/description-of-simulation-log/237/3 "2013-07-08T17:56:13Z")
Also what the third one means? In this example “14” means?
REQUEST “40 actions for 5 days” 14 /people/{userName}/places 1372829594137 1372829594138 1372829594346 1372829594352 OK
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### Author:  [@Excilys](https://community.gatling.io/u/Excilys)
#### Post date: [July 8, 2013, 6:55pm UTC](https://community.gatling.io/t/description-of-simulation-log/237/4 "2013-07-08T18:55:21Z")
- RUN: [https://github.com/excilys/gatling/blob/2.0.0-M3/gatling-core/src/main/scala/io/gatling/core/result/writer/FileDataWriter.scala#L47](https://github.com/excilys/gatling/blob/2.0.0-M3/gatling-core/src/main/scala/io/gatling/core/result/writer/FileDataWriter.scala#L47)
- SCENARIO : [https://github.com/excilys/gatling/blob/2.0.0-M3/gatling-core/src/main/scala/io/gatling/core/result/writer/FileDataWriter.scala#L56](https://github.com/excilys/gatling/blob/2.0.0-M3/gatling-core/src/main/scala/io/gatling/core/result/writer/FileDataWriter.scala#L56)
- REQUEST (previously ACTION): [https://github.com/excilys/gatling/blob/2.0.0-M3/gatling-core/src/main/scala/io/gatling/core/result/writer/FileDataWriter.scala#L71](https://github.com/excilys/gatling/blob/2.0.0-M3/gatling-core/src/main/scala/io/gatling/core/result/writer/FileDataWriter.scala#L71)
- GROUP: [https://github.com/excilys/gatling/blob/2.0.0-M3/gatling-core/src/main/scala/io/gatling/core/result/writer/FileDataWriter.scala#L93](https://github.com/excilys/gatling/blob/2.0.0-M3/gatling-core/src/main/scala/io/gatling/core/result/writer/FileDataWriter.scala#L93)
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### Author:  [@Shawna](https://community.gatling.io/u/Shawna)
#### Post date: [July 8, 2013, 11:07pm UTC](https://community.gatling.io/t/description-of-simulation-log/237/5 "2013-07-08T23:07:10Z")
Oh, got it, it is the userID