SQL: relax version lock between server and clients (#56148) (#56223)

* Relax version lock between ES/SQL and clients

Allow older-than-server clients to connect, if these are past or on a
certain min release.

(cherry picked from commit 108f907297542ce649aa7304060aaf0a504eb699)

x-pack/plugin/sql/jdbc/src/test/java/org/elasticsearch/xpack/sql/jdbc/VersionParityTests.java

@@ -26,7 +26,8 @@ import java.sql.SQLException;
 public class VersionParityTests extends WebServerTestCase {
 
     public void testExceptionThrownOnIncompatibleVersions() throws IOException, SQLException {
-        Version version = VersionUtils.randomVersionBetween(random(), Version.V_6_0_0, VersionUtils.getPreviousVersion(Version.CURRENT));
+        Version version = VersionUtils.randomVersionBetween(random(), null, VersionUtils.getPreviousVersion(Version.V_7_7_0));
+        logger.info("Checking exception is thrown for version {}", version);
         prepareResponse(version);
         
         String url = JdbcConfiguration.URL_PREFIX + webServerAddress();
@@ -37,11 +38,14 @@ public class VersionParityTests extends WebServerTestCase {
     }
     
     public void testNoExceptionThrownForCompatibleVersions() throws IOException {
-        prepareResponse(null);
-        
         String url = JdbcConfiguration.URL_PREFIX + webServerAddress();
+        Version version = Version.CURRENT;
         try {
-            new JdbcHttpClient(JdbcConfiguration.create(url, null, 0));
+            do {
+                prepareResponse(version);
+                new JdbcHttpClient(JdbcConfiguration.create(url, null, 0));
+                version = VersionUtils.getPreviousVersion(version);
+            } while (version.compareTo(Version.V_7_7_0) >= 0);
         } catch (SQLException sqle) {
             fail("JDBC driver version and Elasticsearch server version should be compatible. Error: " + sqle);
         }

x-pack/plugin/sql/sql-action/src/main/java/org/elasticsearch/xpack/sql/action/AbstractSqlQueryRequest.java

@@ -27,6 +27,7 @@ import org.elasticsearch.xpack.sql.proto.Mode;
 import org.elasticsearch.xpack.sql.proto.Protocol;
 import org.elasticsearch.xpack.sql.proto.RequestInfo;
 import org.elasticsearch.xpack.sql.proto.SqlTypedParamValue;
+import org.elasticsearch.xpack.sql.proto.SqlVersion;
 
 import java.io.IOException;
 import java.time.ZoneId;
@@ -218,13 +219,13 @@ public abstract class AbstractSqlQueryRequest extends AbstractSqlRequest impleme
         ActionRequestValidationException validationException = null;
         // the version field is mandatory for drivers and CLI
         Mode mode = requestInfo().mode();
-        if (mode != null && (Mode.isDedicatedClient(mode))) {
+        if (Mode.isDedicatedClient(mode)) {
             if (requestInfo().version() == null) {
                 if (Strings.hasText(query())) {
                     validationException = addValidationError("[version] is required for the [" + mode.toString() + "] client",
                         validationException);
                 }
-            } else if (requestInfo().version().equals(Version.CURRENT.toString()) == false) {
+            } else if (SqlVersion.isClientCompatible(requestInfo().version()) == false) {
                 validationException = addValidationError("The [" + requestInfo().version() + "] version of the [" +
                         mode.toString() + "] " + "client is not compatible with Elasticsearch version [" + Version.CURRENT + "]",
                     validationException);

x-pack/plugin/sql/sql-cli/src/test/java/org/elasticsearch/xpack/sql/cli/CliSessionTests.java

@@ -5,9 +5,11 @@
  */
 package org.elasticsearch.xpack.sql.cli;
 
+import org.elasticsearch.Version;
 import org.elasticsearch.cluster.ClusterName;
 import org.elasticsearch.common.UUIDs;
 import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.test.VersionUtils;
 import org.elasticsearch.xpack.sql.cli.command.CliSession;
 import org.elasticsearch.xpack.sql.client.ClientException;
 import org.elasticsearch.xpack.sql.client.ClientVersion;
@@ -47,7 +49,8 @@ public class CliSessionTests extends ESTestCase {
 
     public void testWrongServerVersion() throws Exception {
         HttpClient httpClient = mock(HttpClient.class);
-        SqlVersion version = new SqlVersion((int)SqlVersion.V_7_7_0.major, SqlVersion.V_7_7_0.minor - 1, 0);
+        Version v = VersionUtils.randomVersionBetween(random(), null, VersionUtils.getPreviousVersion(Version.V_7_7_0));
+        SqlVersion version = new SqlVersion(v.major, v.minor, v.revision);
         when(httpClient.serverInfo()).thenReturn(new MainResponse(randomAlphaOfLength(5), version.toString(),
                 ClusterName.DEFAULT.value(), UUIDs.randomBase64UUID()));
         CliSession cliSession = new CliSession(httpClient);
@@ -61,18 +64,9 @@ public class CliSessionTests extends ESTestCase {
 
     public void testHigherServerVersion() throws Exception {
         HttpClient httpClient = mock(HttpClient.class);
-        byte minor;
+        Version v = VersionUtils.randomVersionBetween(random(), Version.V_7_7_0, null);
-        byte major;
+        SqlVersion version = new SqlVersion(v.major, v.minor, v.revision);
-        if (randomBoolean()) {
+        when(httpClient.serverInfo()).thenReturn(new MainResponse(randomAlphaOfLength(5), version.toString(),
-            minor = ClientVersion.CURRENT.minor;
-            major = (byte) (ClientVersion.CURRENT.major + 1);
-        } else {
-            minor = (byte) (ClientVersion.CURRENT.minor + 1);
-            major = ClientVersion.CURRENT.major;
-
-        }
-        when(httpClient.serverInfo()).thenReturn(new MainResponse(randomAlphaOfLength(5),
-            SqlVersion.fromString(major + "." + minor + ".23").toString(),
             ClusterName.DEFAULT.value(), UUIDs.randomBase64UUID()));
         CliSession cliSession = new CliSession(httpClient);
         cliSession.checkConnection();

x-pack/plugin/sql/sql-proto/src/main/java/org/elasticsearch/xpack/sql/proto/SqlVersion.java

@@ -141,4 +141,9 @@ public class SqlVersion implements Comparable<SqlVersion>{
     public static boolean hasVersionCompatibility(SqlVersion version) {
         return version.compareTo(V_7_7_0) >= 0;
     }
+
+    public static boolean isClientCompatible(SqlVersion version) {
+        /* only client's of version 7.7.0 and later are supported as backwards compatible */
+        return V_7_7_0.compareTo(version) <= 0;
+    }
 }