def tasks = ["1": { build job: 'testGrab', parameters: [string(name: 'id', value: '1')] }
            , "2": { build job: 'testGrab', parameters: [string(name: 'id', value: '2')] }
            , "3": { build job: 'testGrab', parameters: [string(name: 'id', value: '3')] }
            , "4": { build job: 'testGrab', parameters: [string(name: 'id', value: '4')] }
            , "5": { build job: 'testGrab', parameters: [string(name: 'id', value: '5')] }
            , "6": { build job: 'testGrab', parameters: [string(name: 'id', value: '6')] }
            , "7": { build job: 'testGrab', parameters: [string(name: 'id', value: '7')] }
            , "8": { build job: 'testGrab', parameters: [string(name: 'id', value: '8')] }
            , "9": { build job: 'testGrab', parameters: [string(name: 'id', value: '9')] }
            , "10": { build job: 'testGrab', parameters: [string(name: 'id', value: '10')] }
            , "11": { build job: 'testGrab', parameters: [string(name: 'id', value: '11')] }
            , "12": { build job: 'testGrab', parameters: [string(name: 'id', value: '12')] }
            , "13": { build job: 'testGrab', parameters: [string(name: 'id', value: '13')] }
            , "14": { build job: 'testGrab', parameters: [string(name: 'id', value: '14')] }
            ]
parallel tasks 

@Grab(group = 'org.apache.kafka', module = 'kafka-clients', version = '2.0.0')
import org.apache.kafka.clients.producer.KafkaProducer
sleep 10
echo 'hello' 

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
General error during conversion: Error grabbing Grapes -- [unresolved dependency: org.apache.kafka#kafka-clients;2.0.0: not found]

java.lang.RuntimeException: Error grabbing Grapes -- [unresolved dependency: org.apache.kafka#kafka-clients;2.0.0: not found]
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480)
	at org.codehaus.groovy.reflection.CachedConstructor.invoke(CachedConstructor.java:83)
	at org.codehaus.groovy.reflection.CachedConstructor.doConstructorInvoke(CachedConstructor.java:77)
	at org.codehaus.groovy.runtime.callsite.ConstructorSite$ConstructorSiteNoUnwrap.callConstructor(ConstructorSite.java:84)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:250)
	at groovy.grape.GrapeIvy.getDependencies(GrapeIvy.groovy:422)
	at jdk.internal.reflect.GeneratedMethodAccessor129.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSite.invoke(PogoMetaMethodSite.java:169)
	at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.callCurrent(PogoMetaMethodSite.java:59)
	at groovy.grape.GrapeIvy.resolve(GrapeIvy.groovy:569)
	at groovy.grape.GrapeIvy$resolve$1.callCurrent(Unknown Source)
	at groovy.grape.GrapeIvy.resolve(GrapeIvy.groovy:536)
	at groovy.grape.GrapeIvy$resolve$0.callCurrent(Unknown Source)
	at groovy.grape.GrapeIvy.grab(GrapeIvy.groovy:254)
	at groovy.grape.Grape.grab(Grape.java:167)
	at groovy.grape.GrabAnnotationTransformation.visit(GrabAnnotationTransformation.java:376)
	at org.codehaus.groovy.transform.ASTTransformationVisitor$3.call(ASTTransformationVisitor.java:346)
	at org.codehaus.groovy.control.CompilationUnit.applyToSourceUnits(CompilationUnit.java:966)
	at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:626)
	at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:602)
	at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:579)
	at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:323)
	at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:293)
	at PluginClassLoader for script-security//org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovySandbox$Scope.parse(GroovySandbox.java:163)
	at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsGroovyShell.doParse(CpsGroovyShell.java:190)
	at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsGroovyShell.reparse(CpsGroovyShell.java:175)
	at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.parseScript(CpsFlowExecution.java:652)
	at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.start(CpsFlowExecution.java:598)
	at PluginClassLoader for workflow-job//org.jenkinsci.plugins.workflow.job.WorkflowRun.run(WorkflowRun.java:335)
	at hudson.model.ResourceController.execute(ResourceController.java:101)
	at hudson.model.Executor.run(Executor.java:446)

1 error

	at org.codehaus.groovy.control.ErrorCollector.failIfErrors(ErrorCollector.java:309)
	at org.codehaus.groovy.control.ErrorCollector.addException(ErrorCollector.java:155)
	at org.codehaus.groovy.control.SourceUnit.addException(SourceUnit.java:335)
	at groovy.grape.GrabAnnotationTransformation.visit(GrabAnnotationTransformation.java:385)
	at org.codehaus.groovy.transform.ASTTransformationVisitor$3.call(ASTTransformationVisitor.java:346)
	at org.codehaus.groovy.control.CompilationUnit.applyToSourceUnits(CompilationUnit.java:966)
	at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:626)
	at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:602)
	at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:579)
	at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:323)
	at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:293)
	at PluginClassLoader for script-security//org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovySandbox$Scope.parse(GroovySandbox.java:163)
	at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsGroovyShell.doParse(CpsGroovyShell.java:190)
	at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsGroovyShell.reparse(CpsGroovyShell.java:175)
	at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.parseScript(CpsFlowExecution.java:652)
	at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.start(CpsFlowExecution.java:598)
	at PluginClassLoader for workflow-job//org.jenkinsci.plugins.workflow.job.WorkflowRun.run(WorkflowRun.java:335)
	at hudson.model.ResourceController.execute(ResourceController.java:101)
	at hudson.model.Executor.run(Executor.java:446)
Finished: FAILURE 

... This part of the cache can be shared if you use a well suited lock strategy. 

lockStrategy ... defaults to no-lock 

no-lock
This lock strategy actually performs no locking at all, and thus should not be used in an environment where the cache is shared by multiple processes. 

<ivysettings>
    <settings defaultResolver="downloadGrapes"/>
    <caches lockStrategy="artifact-lock-nio" />
    ...
</ivysettings>