[agent/plugin] Move FILTER_LENGTH_LIMIT to config.plugin.mongodb (#3820)

* move FILTER_LENGTH_LIMIT

* fix checkstyle

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/Config.java

@@ -19,13 +19,14 @@
 
 package org.apache.skywalking.apm.agent.core.conf;
 
-import java.util.HashMap;
-import java.util.Map;
 import org.apache.skywalking.apm.agent.core.context.trace.TraceSegment;
 import org.apache.skywalking.apm.agent.core.logging.core.LogLevel;
 import org.apache.skywalking.apm.agent.core.logging.core.LogOutput;
 import org.apache.skywalking.apm.agent.core.logging.core.WriterFactory;
 
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * This is the core config in sniffer agent.
  *
@@ -220,6 +221,14 @@ public class Config {
              * include parameters.
              */
             public static boolean TRACE_PARAM = false;
+
+            /**
+             * For the sake of performance, SkyWalking won't save the entire parameters string into the tag, but only
+             * the first {@code FILTER_LENGTH_LIMIT} characters.
+             *
+             * Set a negative number to save the complete parameter string to the tag.
+             */
+            public static int FILTER_LENGTH_LIMIT = 256;
         }
 
         public static class Elasticsearch {

apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/support/MongoConstants.java

@@ -31,8 +31,6 @@ public class MongoConstants {
 
     public static final String MONGO_DB_OP_PREFIX = "MongoDB/";
 
-    public static final int FILTER_LENGTH_LIMIT = 256;
-
     public static final String EMPTY = "";
 
 }

apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/support/MongoOperationHelper.java

@@ -23,7 +23,24 @@ import com.mongodb.bulk.DeleteRequest;
 import com.mongodb.bulk.InsertRequest;
 import com.mongodb.bulk.UpdateRequest;
 import com.mongodb.bulk.WriteRequest;
-import com.mongodb.operation.*;
+import com.mongodb.operation.CountOperation;
+import com.mongodb.operation.CreateCollectionOperation;
+import com.mongodb.operation.CreateIndexesOperation;
+import com.mongodb.operation.CreateViewOperation;
+import com.mongodb.operation.DeleteOperation;
+import com.mongodb.operation.DistinctOperation;
+import com.mongodb.operation.FindAndDeleteOperation;
+import com.mongodb.operation.FindAndReplaceOperation;
+import com.mongodb.operation.FindAndUpdateOperation;
+import com.mongodb.operation.FindOperation;
+import com.mongodb.operation.GroupOperation;
+import com.mongodb.operation.InsertOperation;
+import com.mongodb.operation.ListCollectionsOperation;
+import com.mongodb.operation.MapReduceToCollectionOperation;
+import com.mongodb.operation.MapReduceWithInlineResultsOperation;
+import com.mongodb.operation.MixedBulkWriteOperation;
+import com.mongodb.operation.UpdateOperation;
+import org.apache.skywalking.apm.agent.core.conf.Config;
 import org.bson.BsonDocument;
 
 import java.util.List;
@@ -111,7 +128,8 @@ public class MongoOperationHelper {
             } else if (request instanceof UpdateRequest) {
                 params.append(((UpdateRequest) request).getFilter()).append(",");
             }
-            if (params.length() > MongoConstants.FILTER_LENGTH_LIMIT) {
+            final int filterLengthLimit = Config.Plugin.MongoDB.FILTER_LENGTH_LIMIT;
+            if (filterLengthLimit > 0 && params.length() > filterLengthLimit) {
                 params.append("...");
                 break;
             }
@@ -121,8 +139,9 @@ public class MongoOperationHelper {
 
     private static String limitFilter(String filter) {
         final StringBuilder params = new StringBuilder();
-        if (filter.length() > MongoConstants.FILTER_LENGTH_LIMIT) {
-            return params.append(filter, 0, MongoConstants.FILTER_LENGTH_LIMIT).append("...").toString();
+        final int filterLengthLimit = Config.Plugin.MongoDB.FILTER_LENGTH_LIMIT;
+        if (filterLengthLimit > 0 && filter.length() > filterLengthLimit) {
+            return params.append(filter, 0, filterLengthLimit).append("...").toString();
         } else {
             return filter;
         }

docs/en/setup/service-agent/java-agent/README.md

@@ -97,6 +97,7 @@ property key | Description | Default |
 `dictionary.endpoint_name_buffer_size`|The buffer size of endpoint names and peer|`1000 * 10000`|
 `plugin.peer_max_length `|Peer maximum description limit.|`200`|
 `plugin.mongodb.trace_param`|If true, trace all the parameters in MongoDB access, default is false. Only trace the operation, not include parameters.|`false`|
+`plugin.mongodb.filter_length_limit`|If set to positive number, the `WriteRequest.params` would be truncated to this length, otherwise it would be completely saved, which may cause performance problem.|`256`|
 `plugin.elasticsearch.trace_dsl`|If true, trace all the DSL(Domain Specific Language) in ElasticSearch access, default is false.|`false`|
 `plugin.springmvc.use_qualified_name_as_endpoint_name`|If true, the fully qualified method name will be used as the endpoint name instead of the request URL, default is false.|`false`|
 `plugin.toolit.use_qualified_name_as_operation_name`|If true, the fully qualified method name will be used as the operation name instead of the given operation name, default is false.|`false`|