diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 14ee8cb..97c8077 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -2,7 +2,7 @@ image: maven:latest
 
 variables:
   BUILD_PROPS: "-Dbuild.revision=$CI_COMMIT_SHA -Dbuild.branch=$CI_COMMIT_REF_NAME -Dbuild.number=$CI_PIPELINE_IID "
-  MAVEN_CLI_OPTS: " --batch-mode -Dmaven.repo.local=repository -Dfile.encoding=UTF-8 -s .settings/settings.xml"
+  MAVEN_CLI_OPTS: " --batch-mode -Dfile.encoding=UTF-8 -s .mvn/settings.xml -Dmaven.repo.local=.mvn/repository -Dhttp.keepAlive=false -Dmaven.wagon.http.pool=false"
 
 before_script:
   - export CI_JOB_TIMESTAMP="-Dbuild.timestamp=$(date --utc --iso-8601=seconds)"
@@ -10,57 +10,11 @@ before_script:
 cache:
   key: maven
   paths:
-    - repository
-
-build-amazoncorretto:
-  stage: build
-  image: maven:amazoncorretto
-  script:
-    - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
-  retry: 2
-  artifacts:
-    name: amazoncorretto
-    paths:
-      - target/*.jar
-    reports:
-      junit:
-        - target/surefire-reports/*.xml
-        - target/failsafe-reports/*.xml
-
-build-java-14:
-  stage: build
-  image: maven:3-jdk-14
-  script:
-    - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
-  retry: 2
-  artifacts:
-    when: on_failure
-    name: java-14
-    paths:
-      - target/*
-    reports:
-      junit:
-        - target/surefire-reports/*.xml
-        - target/failsafe-reports/*.xml
-
-build-java-11-openj9:
-  stage: build
-  image: maven:3-jdk-11-openj9
-  script:
-    - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
-  retry: 2
-  artifacts:
-    name: java-11-openj9
-    paths:
-      - target/*.jar
-    reports:
-      junit:
-        - target/surefire-reports/*.xml
-        - target/failsafe-reports/*.xml
+    - .mvn/repository
 
 build-java-11:
   stage: build
-  image: maven:3-jdk-11
+  image: $CI_REGISTRY_IMAGE/maven:3-jdk-11
   script:
     - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
   retry: 2
@@ -74,9 +28,39 @@ build-java-11:
         - target/surefire-reports/*.xml
         - target/failsafe-reports/*.xml
 
+build-java-11-openj9:
+  stage: build
+  image: $CI_REGISTRY_IMAGE/maven:3-jdk-11-openj9
+  script:
+    - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
+  retry: 2
+  artifacts:
+    name: java-11-openj9
+    paths:
+      - target/*.jar
+    reports:
+      junit:
+        - target/surefire-reports/*.xml
+        - target/failsafe-reports/*.xml
+
+build-java8:
+  stage: build
+  image: $CI_REGISTRY_IMAGE/maven:3-jdk-8
+  script:
+    - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
+  retry: 2
+  artifacts:
+    name: java-8
+    paths:
+      - target/*.jar
+    reports:
+      junit:
+        - target/surefire-reports/*.xml
+        - target/failsafe-reports/*.xml
+
 build-java-8-openj9:
   stage: build
-  image: maven:3-jdk-8-openj9
+  image: $CI_REGISTRY_IMAGE/maven:3-jdk-8-openj9
   script:
     - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
   retry: 2
@@ -89,16 +73,49 @@ build-java-8-openj9:
         - target/surefire-reports/*.xml
         - target/failsafe-reports/*.xml
 
-build-java8:
+build-java-15:
   stage: build
-  image: maven:3-jdk-8-alpine
+  image: $CI_REGISTRY_IMAGE/maven:3-openjdk-15
   script:
     - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
   retry: 2
   artifacts:
-    name: java-8-alpine
+    when: on_failure
+    name: java-15
     paths:
-      - target/*.jar
+      - target/*
+    reports:
+      junit:
+        - target/surefire-reports/*.xml
+        - target/failsafe-reports/*.xml
+
+build-java-16:
+  stage: build
+  image: $CI_REGISTRY_IMAGE/maven:3-openjdk-16
+  script:
+    - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
+  retry: 2
+  artifacts:
+    when: on_failure
+    name: java-16
+    paths:
+      - target/*
+    reports:
+      junit:
+        - target/surefire-reports/*.xml
+        - target/failsafe-reports/*.xml
+
+build-java-17:
+  stage: build
+  image: $CI_REGISTRY_IMAGE/maven:3-openjdk-17
+  script:
+    - mvn $MAVEN_CLI_OPTS $BUILD_PROPS $CI_JOB_TIMESTAMP verify
+  retry: 2
+  artifacts:
+    when: on_failure
+    name: java-17
+    paths:
+      - target/*
     reports:
       junit:
         - target/surefire-reports/*.xml
@@ -106,7 +123,7 @@ build-java8:
 
 deploy:
   stage: deploy
-  image: maven:3-jdk-11
+  image: $CI_REGISTRY_IMAGE/maven:3-jdk-11
   dependencies:
     - build-java-11
   script:
@@ -118,3 +135,16 @@ deploy:
     - mvn $MAVEN_CLI_OPTS  deploy:deploy-file -Dfile=target/validationtool-${PROJECT_VERSION}-java8-standalone.jar -DgroupId=kosit -DartifactId=validator -Dclassifier="java8-standalone" -Dversion=${PROJECT_VERSION} -Dpackaging=jar -DrepositoryId="gitlab-maven" -Durl=https://projekte.kosit.org/api/v4/projects/7/packages/maven
     - mvn $MAVEN_CLI_OPTS  deploy:deploy-file -Dfile=target/validationtool-${PROJECT_VERSION}-sources.jar -DgroupId=kosit -DartifactId=validator -Dclassifier="sources" -Dversion=${PROJECT_VERSION} -Dpackaging=jar -DrepositoryId="gitlab-maven" -Durl=https://projekte.kosit.org/api/v4/projects/7/packages/maven
   when: manual
+
+create-build-image:
+  stage: deploy
+  image: docker:latest
+  needs: [ ]
+  services:
+    - docker:dind
+  script:
+    - apk add bash
+    - bash .mvn/createBuildImages.sh
+  when: manual
+
+
diff --git a/.mvn/createBuildImages.sh b/.mvn/createBuildImages.sh
new file mode 100644
index 0000000..e3a0111
--- /dev/null
+++ b/.mvn/createBuildImages.sh
@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+TAGS=("3-openjdk-16" "3-jdk-11" "3-jdk-11-openj9" "3-jdk-8" "3-jdk-8-openj9", "3-openjdk-15", "3-openjdk-17")
+
+docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" "$CI_REGISTRY"
+for i in "${TAGS[@]}"
+do
+  echo Creating build image for "$i"
+  {
+    echo "FROM maven:${i}"
+  }  >> Dockerfile
+  docker build -t "$CI_REGISTRY_IMAGE/maven:$i" .
+  docker push "$CI_REGISTRY_IMAGE/maven:${i}"
+  rm Dockerfile
+done
\ No newline at end of file
diff --git a/.mvn/jvm.config b/.mvn/jvm.config
new file mode 100644
index 0000000..423c21f
--- /dev/null
+++ b/.mvn/jvm.config
@@ -0,0 +1 @@
+-Xms128m -Xmx512m
\ No newline at end of file
diff --git a/.mvn/settings.xml b/.mvn/settings.xml
new file mode 100644
index 0000000..9e2bfbe
--- /dev/null
+++ b/.mvn/settings.xml
@@ -0,0 +1,47 @@
+<!--
+  ~ Copyright 2017-2021  Koordinierungsstelle für IT-Standards (KoSIT)
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+
+<settings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/SETTINGS/1.1.0"
+        xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.1.0 http://maven.apache.org/xsd/settings-1.1.0.xsd">
+<!--
+  ~ Copyright 2017-2021  Koordinierungsstelle für IT-Standards (KoSIT)
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~     http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+    <servers>
+        <server>
+            <id>gitlab-maven</id>
+            <configuration>
+                <httpHeaders>
+                    <property>
+                        <name>Job-Token</name>
+                        <value>${env.CI_JOB_TOKEN}</value>
+                    </property>
+                </httpHeaders>
+            </configuration>
+        </server>
+    </servers>
+</settings>
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
index 44e3f80..1c37d2f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -463,6 +463,7 @@
                     <arguments>
                         <!--suppress MavenModelInspection -->
                         <argument>${jacocoFailsafe}</argument>
+                        <argument>-Xmx256m</argument>
                         <argument>-classpath</argument>
                         <classpath />
                         <argument>de.kosit.validationtool.cmd.CommandLineApplication</argument>
diff --git a/src/test/java/de/kosit/validationtool/impl/xml/BaseResolverConfigurationTest.java b/src/test/java/de/kosit/validationtool/impl/xml/BaseResolverConfigurationTest.java
index ca86c93..3d97a4c 100644
--- a/src/test/java/de/kosit/validationtool/impl/xml/BaseResolverConfigurationTest.java
+++ b/src/test/java/de/kosit/validationtool/impl/xml/BaseResolverConfigurationTest.java
@@ -45,10 +45,12 @@ public class BaseResolverConfigurationTest {
     private class TestResolvingStrategy extends StrictRelativeResolvingStrategy {
 
         void setInternalProperty(final SchemaFactory factory, final boolean lenient) {
-            allowExternalSchema(factory, lenient, "quatsch");
+            allowExternalSchema(factory, lenient, NOT_EXISTING_SCHEME);
         }
     }
 
+    public static final String NOT_EXISTING_SCHEME = "not-existing-scheme";
+
     @Rule
     public ExpectedException expectedException = ExpectedException.none();
 
@@ -75,7 +77,7 @@ public class BaseResolverConfigurationTest {
         final TestResolvingStrategy s = new TestResolvingStrategy();
         s.setInternalProperty(sf, true);
         s.setInternalProperty(sf, false);
-        verify(sf, times(2)).setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, "quatsch");
+        verify(sf, times(2)).setProperty(XMLConstants.ACCESS_EXTERNAL_SCHEMA, BaseResolverConfigurationTest.NOT_EXISTING_SCHEME);
     }
 
 }