Challenge upgrading Spring boot to version 2.7.5 with 7.17 client and Elasticsearch 7.10.2 - spring-boot

Question

I upgraded my Spring boot version to 2.7.5 and spring-boot-starter-data-elasticsearch client to 7.17. I have Amazon Elasticsearch Service version 7.10.2 running and at the moment I can not upgrade the Elasticsearch because of various reasons.
I have made the necessary code changes but I get the below error:
Any advice on how to update the Spring book version without upgrading Elasticsearch is highly appreciated.
Thank you.
POM
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.5</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<maven.test.redirectOutputToFile>false</maven.test.redirectOutputToFile>
<java.version>11</java.version>
<elasticsearch.version>7.17.6</elasticsearch.version>
</properties>
org.elasticsearch.ElasticsearchException: Invalid or missing build flavor [oss]
at org.elasticsearch.client.RestHighLevelClient.performClientRequest(RestHighLevelClient.java:2701) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]
at org.elasticsearch.client.RestHighLevelClient.internalPerformRequest(RestHighLevelClient.java:2171) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]
at org.elasticsearch.client.RestHighLevelClient.performRequest(RestHighLevelClient.java:2137) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]
at org.elasticsearch.client.RestHighLevelClient.performRequestAndParseEntity(RestHighLevelClient.java:2105) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]
at org.elasticsearch.client.ClusterClient.health(ClusterClient.java:151) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]
at ai.cyr3con.gargoyl3.api.config.elasticsearch.ElasticsearchClient.health(ElasticsearchClient.java:63) ~[classes/:na]
at ai.cyr3con.gargoyl3.api.common.elasticsearch.repositories.ClusterManagingElasticsearchRepository.health(ClusterManagingElasticsearchRepository.java:15) ~[classes/:na]
at ai.cyr3con.gargoyl3.api.common.elasticsearch.repositories.ClusterManagingElasticsearchRepository$$FastClassBySpringCGLIB$$b6605bb6.invoke(<generated>) ~[classes/:na]
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:793) ~[spring-aop-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763) ~[spring-aop-5.3.23.jar:5.3.23]
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:137) ~[spring-tx-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763) ~[spring-aop-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:708) ~[spring-aop-5.3.23.jar:5.3.23]
at ai.cyr3con.gargoyl3.api.common.elasticsearch.repositories.ClusterManagingElasticsearchRepository$$EnhancerBySpringCGLIB$$c638bfde.health(<generated>) ~[classes/:na]
at ai.cyr3con.gargoyl3.api.config.actuator.AbstractElasticsearchHealthIndicator.doHealthCheck(AbstractElasticsearchHealthIndicator.java:31) ~[classes/:na]
at org.springframework.boot.actuate.health.AbstractHealthIndicator.health(AbstractHealthIndicator.java:82) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthIndicator.getHealth(HealthIndicator.java:37) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpoint.getHealth(HealthEndpoint.java:94) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpoint.getHealth(HealthEndpoint.java:41) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpointSupport.getLoggedHealth(HealthEndpointSupport.java:172) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpointSupport.getContribution(HealthEndpointSupport.java:145) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpointSupport.getAggregateContribution(HealthEndpointSupport.java:156) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpointSupport.getContribution(HealthEndpointSupport.java:141) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpointSupport.getHealth(HealthEndpointSupport.java:110) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpointSupport.getHealth(HealthEndpointSupport.java:81) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpoint.health(HealthEndpoint.java:88) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.health.HealthEndpoint.health(HealthEndpoint.java:78) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:282) ~[spring-core-5.3.23.jar:5.3.23]
at org.springframework.boot.actuate.endpoint.invoke.reflect.ReflectiveOperationInvoker.invoke(ReflectiveOperationInvoker.java:74) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.endpoint.annotation.AbstractDiscoveredOperation.invoke(AbstractDiscoveredOperation.java:60) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.endpoint.jmx.EndpointMBean.invoke(EndpointMBean.java:122) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at org.springframework.boot.actuate.endpoint.jmx.EndpointMBean.invoke(EndpointMBean.java:97) ~[spring-boot-actuator-2.7.5.jar:2.7.5]
at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:809) ~[na:na]
at java.management/com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) ~[na:na]
at java.management.rmi/javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1466) ~[na:na]
at java.management.rmi/javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1307) ~[na:na]
at java.management.rmi/javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1399) ~[na:na]
at java.management.rmi/javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:827) ~[na:na]
at java.base/jdk.internal.reflect.GeneratedMethodAccessor205.invoke(Unknown Source) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
at java.rmi/sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:359) ~[na:na]
at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:200) ~[na:na]
at java.rmi/sun.rmi.transport.Transport$1.run(Transport.java:197) ~[na:na]
at java.base/java.security.AccessController.doPrivileged(Native Method) ~[na:na]
at java.rmi/sun.rmi.transport.Transport.serviceCall(Transport.java:196) ~[na:na]
at java.rmi/sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:562) ~[na:na]
at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:796) ~[na:na]
at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:677) ~[na:na]
at java.base/java.security.AccessController.doPrivileged(Native Method) ~[na:na]
at java.rmi/sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:676) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at java.base/java.lang.Thread.run(Thread.java:829) ~[na:na]

Answer 1

The error you see comes from a change that Elasticsearch did after the 7.10 version: The Elasticsearch client checks the version of the Elasticsearch cluster it connects to and refuses the connection if this is not an Elasticsearch product in the correct version. This is nothing that Spring Data Elasticsearch was able to influence.
Spring Boot 2.7.5 (and Spring Data Elasticsearch 4.4) are built against Elasticsearch client libraries in version 7.17.
It should be possible to fix the version of the Elasticsearch client library to 7.10, but this will almost certainly cause errors because the API change between that versions, classes were moved to different packages for example.
Spring Data Elasticsearch 4.1.x used Elasticsearch 7.9.3, 4.2 already was on 7.12. Fixing Spring Data Elasticsearch to 4.1 might work, no guarantees. 4.1.x has reached EOL in November 2021.