# Gatling 2 fails 7U6 SDK check for IBM SDKs
**URL:** https://community.gatling.io/t/gatling-2-fails-7u6-sdk-check-for-ibm-sdks/1691
**Category:** Gatling (Open-Source)
**Created:** [November 13, 2014, 7:49pm UTC](https://community.gatling.io/t/gatling-2-fails-7u6-sdk-check-for-ibm-sdks/1691 "2014-11-13T19:49:27Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Harold\_Everett](https://community.gatling.io/u/Harold_Everett)
#### Post date: [November 13, 2014, 7:49pm UTC](https://community.gatling.io/t/gatling-2-fails-7u6-sdk-check-for-ibm-sdks/1691/1 "2014-11-13T19:49:27Z")
Currently, Gatling is not IBM JDK friendly. You can continue to run it from a non IBM JDK. Unfortunately, my only driving machine is zLinux and IBM is the only SDK for zLinux.
I was trying to run from zLinux, no matter what IBM SDK you try, the message you will see is:
zmasonlx1:/var/gatling/bin # ./gatling.sh -s workloadSimulation/RWTServlet4
GATLING\_HOME is set to /var/gatling
Exception in thread “main” java.lang.UnsupportedOperationException: Gatling requires Java \>= 7u6
The version I was trying to use is higher than 7U6:
zmasonlx1:/var/gatling/bin # java -version
java version “1.7.0”
Java™ SE Runtime Environment (build pxz6470\_27sr2ifix-20141107\_04(SR2+IV66608+IV66375))
IBM J9 VM (build 2.7, JRE 1.7.0 Linux s390x-64 Compressed References 20141107\_221193 (JIT enabled, AOT enabled)
J9VM - R27\_Java727\_SR2\_20141107\_0840\_B221193
JIT - tr.r13.java\_20141003\_74587.03
GC - R27\_Java727\_SR2\_20141107\_0840\_B221193\_CMPRSS
J9CL - 20141107\_221193)
JCL - 20141004\_01 based on Oracle 7u71-b13
zmasonlx1:/var/gatling/bin # java -fullversion
java full version JRE 1.7.0 IBM Linux build pxz6470\_27sr2ifix-20141107\_04(SR2+IV66608+IV66375)
It must be keying on a String that does not match what we produce.
If I can help figure out the appropriate string to match, I will.
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### Author:  [@Excilys](https://community.gatling.io/u/Excilys)
#### Post date: [November 13, 2014, 8:05pm UTC](https://community.gatling.io/t/gatling-2-fails-7u6-sdk-check-for-ibm-sdks/1691/2 "2014-11-13T20:05:16Z")
We do some optimizations that assume the new java.lang.String implementation that was introduced with OpenJDK/Hotspot 7u6, where they removed the offset and length fields. I can’t tell if and when IBM did the same move in some of their updates.