MongoDB Rebuild Index

Standalone Mode

1. Enter the storage component container

   docker exec -it $(docker ps | grep mingdaoyun-sc | awk '{print $1}') bash

Cluster Mode or External MongoDB

1. Log in to the MongoDB server (if in replica set mode, log in to the PRIMARY node)

2. Create a reIndex.js script file to rebuild user-defined indexes under the mdwsrows database

   Content of reIndex.js Script File

   var targetDbName = "mdwsrows";  // Target database
   
   // Collection whitelist; collections in the whitelist will not have their indexes rebuilt
   var collectionWhitelist = [
       "discussion",
       "rowrelations",
       "workSheetRowTopic",
       "workSheetTopic",
       "wslogs"
   ];
   
   // Index whitelist; indexes in the whitelist will not be rebuilt
   var indexWhitelist = [
       "_id_",
       "idx_ctime",
       "idx_utime",
       "uk_rowid",
       "idx_tp_status",
       "idx_thirdprimary"
   ];
   
   // DateTime formatting function
   function formatDateTime() {
       var now = new Date();
       var utc8Time = new Date(now.getTime() + (8 * 60 * 60 * 1000));
       return utc8Time.toISOString().replace('Z', '+08:00');
   }
   
   // Formatting output function
   function printHeader(text) {
       print("\n" + "=".repeat(100));
       print(text);
       print("=".repeat(100));
   }
   
   function printSection(text) {
       print("\n" + "-".repeat(80));
       print(text);
       print("-".repeat(80));
   }
   
   function printTimedAction(time, action) {
       print(`\n[${time}] ${action}`);
   }
   
   // Format JSON with consistent indentation
   function formatJSON(obj, indent = 5) {
       return JSON.stringify(obj, null, 2)
           .split('\n')
           .map((line, i) => i === 0 ? line : ' '.repeat(indent) + line)
           .join('\n');
   }
   
   // Format createIndex command
   function formatCreateIndexCommand(collName, key, options) {
       return `db.${collName}.createIndex(${formatJSON(key)},\n     ${formatJSON(options)})`;
   }
   
   function printCommand(command) {
       print("  └─ Execute:");
       print("     " + command);
   }
   
   function printCompletion(seconds) {
       print(`  └─ ✓ Completed in ${seconds.toFixed(3)} seconds\n`);
   }
   
   // Connect to the target database
   var targetDb = db.getSiblingDB(targetDbName);
   var startTime = formatDateTime();
   
   printHeader("MongoDB Index Rebuild Process");
   print(`\n• Start Time: ${startTime}`);
   print(`• Target Database: ${targetDb.getName()}`);
   
   // Get all collections to rebuild by filtering the collection whitelist
   var collections = targetDb.getCollectionNames().filter(function(collName) {
       return !collectionWhitelist.includes(collName) &&
              !collName.startsWith('system.');
   });
   
   print(`• Total Collections: ${collections.length}`);
   
   collections.forEach(function(collName, index) {
       var coll = targetDb.getCollection(collName);
       var stats = coll.stats();
       
       // Output collection info and progress
       printSection(`Processing Collection [${index + 1}/${collections.length}]: ${collName}`);
       print(`\n• Document Count: ${stats.count}`);
       print(`• Storage Size: ${stats.storageSize} bytes`);
       
       // Get indexes to rebuild by filtering the index whitelist
       var indexes = coll.getIndexes();
       var rebuildIndexes = indexes.filter(function(idx) {
           return !indexWhitelist.includes(idx.name);
       });
       
       if (rebuildIndexes.length === 0) {
           print("\n✓ No indexes need to be rebuilt.");
           return;
       }
       
       // Output index rebuild plan
       print(`\n• Indexes to Rebuild (${rebuildIndexes.length}):`);
       rebuildIndexes.forEach(function(idx) {
           print(`  ├─ Name: ${idx.name.padEnd(20)}`);
           print(`  │  Key: ${JSON.stringify(idx.key)}`);
       });
       
       // Rebuild each index
       rebuildIndexes.forEach(function(idx) {
           var key = idx.key;
           var options = {};
           
           // Copy index configuration, excluding system attributes
           for (var prop in idx) {
               if (!["v", "ns", "background"].includes(prop)) {
                   options[prop] = idx[prop];
               }
           }
           options.background = true;  // Build index in background
           
           try {
               // Drop the old index
               var dropTime = formatDateTime();
               printTimedAction(dropTime, `Dropping Index: ${idx.name}`);
               printCommand(`db.${collName}.dropIndex("${idx.name}")`);
               
               var dropStart = new Date();
               coll.dropIndex(idx.name);
               var dropEnd = new Date();
               printCompletion((dropEnd - dropStart)/1000);
               
               // Create a new index
               var createTime = formatDateTime();
               printTimedAction(createTime, `Creating Index: ${idx.name}`);
               printCommand(formatCreateIndexCommand(collName, key, options));
               
               var createStart = new Date();
               coll.createIndex(key, options);
               var createEnd = new Date();
               printCompletion((createEnd - createStart)/1000);
               
           } catch (e) {
               print(`  └─ ✗ Error: ${e.message}`);
               print("     Skipping this index...\n");
           }
       });
   });
   
   var endTime = formatDateTime();
   printHeader("Process Completed");
   print(`\n• End Time: ${endTime}`);

3. Execute the script

   MongoDB without Authentication

   nohup mongo mongodb://127.0.0.1:27017/admin --quiet reIndex.js >> reIndex_output.log 2>&1 &

   • The execution log will be output to the reIndex_output.log file

   MongoDB with Authentication

   nohup mongo mongodb://root:password@127.0.0.1:27017/admin --quiet reIndex.js >> reIndex_output.log 2>&1 &

   • If the mongo command is not in the PATH variable, you need to specify the absolute path
   • The execution log will be output to the reIndex_output.log file

4. Monitor the log and wait for the script to complete its execution (the log will end with Process Complete and End Time)

5. Create a reIndexWithCmd.js script file to rebuild some indexes that HAP system relies on

   Content of reIndexWithCmd.js Script File

   // ====================================================================
   //                          CONFIGURATION
   // ====================================================================
   // Configure the databases and their whitelist collections for index rebuilding here
   // Format: "Database Name": ["Collection to skip 1", "Collection to skip 2..."]
   // Use an empty array [] if all collections in a database need index rebuilding
   var targetDatabases = {
       "mdpost": [],
       "MDHistory": []
   };
   // ====================================================================
   
   
   // Formatting output function (no modification needed)
   function printHeader(text) {
       print("\n" + "=".repeat(100));
       print(text);
       print("=".repeat(100));
   }
   
   function printSection(text) {
       print("\n" + "-".repeat(80));
       print(text);
       print("-".repeat(80));
   }
   
   function formatDateTime() {
       var now = new Date();
       var utc8Time = new Date(now.getTime() + (8 * 60 * 60 * 1000));
       return utc8Time.toISOString().replace('Z', '+08:00');
   }
   
   function formatJSON(obj, indent = 5) {
       if (obj === undefined || obj === null) {
           return "Not available";
       }
       return JSON.stringify(obj, null, 2)
           .split('\n')
           .map((line, i) => i === 0 ? line : ' '.repeat(indent) + line)
           .join('\n');
   }
   
   function formatFileSize(bytes) {
       if (bytes === undefined || bytes === null) return "N/A";
       return (bytes / 1024 / 1024).toFixed(2) + " MB";
   }
   
   function printTimedAction(time, action) {
       print(`\n[${time}] ${action}`);
   }
   
   function printCompletion(seconds) {
       print(`  └─ ✓ Completed in ${seconds.toFixed(3)} seconds\n`);
   }
   
   // ====================================================================
   //                          SCRIPT EXECUTION
   // ====================================================================
   
   var overallStartTime = formatDateTime();
   printHeader("MongoDB Multi-Database Index Rebuild Process Started");
   print(`\n• Overall Start Time: ${overallStartTime}`);
   print(`• Databases to Process: ${Object.keys(targetDatabases).join(', ')}`);
   
   // Iterate through all configured databases
   for (var dbName in targetDatabases) {
       if (targetDatabases.hasOwnProperty(dbName)) {
           
           printHeader(`Processing Database: [ ${dbName} ]`);
   
           // Connect to the target database
           var currentDb = db.getSiblingDB(dbName);
           
           // Get the collection blacklist (collections to skip) for the current database
           var excludedCollections = targetDatabases[dbName];
   
           print(`\n• Target Database: ${currentDb.getName()}`);
           print(`• Excluded Collections: ${formatJSON(excludedCollections)}`);
   
           // Get all collections
           var collections = currentDb.getCollectionNames();
           // Filter out collections in the blacklist and system collections
           var validCollections = collections.filter(collection => 
               !excludedCollections.includes(collection) && !collection.startsWith('system.')
           );
   
           print(`• Total Collections to Process in this DB: ${validCollections.length}`);
           
           if (validCollections.length === 0) {
               print("\nNo collections to process in this database. Moving to the next one.");
               continue;
           }
   
           validCollections.forEach(function(collection, index) {
               try {
                   // Get collection statistics
                   var stats = currentDb[collection].stats();
                   
                   // Output collection info and progress
                   printSection(`Processing Collection [${index + 1}/${validCollections.length}]: ${collection}`);
                   print(`\n• Collection Statistics:`);
                   print(`  ├─ Storage Size: ${formatFileSize(stats.storageSize)}`);
                   print(`  └─ Document Count: ${(stats.count || 0).toLocaleString()}`);
                   
                   // Get current index information
                   var indexes = currentDb[collection].getIndexes();
                   print(`\n• Current Indexes (${indexes.length}):`);
                   indexes.forEach(function(idx, i) {
                       const isLast = i === indexes.length - 1;
                       print(`  ${isLast ? '└' : '├'}─ Name: ${idx.name.padEnd(20)}`);
                       print(`  ${isLast ? ' ' : '│'}  Key: ${formatJSON(idx.key)}`);
                   });
                   
                   // Execute reIndex
                   var execTime = formatDateTime();
                   printTimedAction(execTime, "Executing reIndex()");
                   print("  └─ Execute:");
                   print(`     db.getSiblingDB('${dbName}').getCollection('${collection}').reIndex()`);
                   
                   var startExec = new Date();
                   var result = currentDb[collection].reIndex();
                   var endExec = new Date();
                   
                   if (result.ok === 1) {
                       printCompletion((endExec - startExec)/1000);
                       
                       print("• Operation Results:");
                       print(`  ├─ Previous Index Count: ${result.nIndexesWas}`);
                       print(`  ├─ Current Index Count: ${result.nIndexes}`);
                       
                       if (result.operationTime !== undefined) {
                           print(`  ├─ Operation Time: ${formatJSON(result.operationTime)}`);
                       } else {
                           print(`  ├─ Operation Time: Not available (non-replica set deployment)`);
                       }
                       
                       if (result.$clusterTime !== undefined) {
                           print(`  └─ Cluster Time: ${formatJSON(result.$clusterTime)}`);
                       } else {
                           print(`  └─ Cluster Time: Not available (non-replica set deployment)`);
                       }
                       
                   } else {
                       print(`  └─ ✗ ReIndex failed: ${formatJSON(result)}`);
                   }
               } catch (e) {
                   print(`  └─ ✗ Error: ${e.message}`);
                   print("     Skipping this collection...\n");
               }
           });
       }
   }
   
   var overallEndTime = formatDateTime();
   printHeader("Process Completed");
   print(`\n• Overall End Time: ${overallEndTime}`);
   

6. Execute the script

   MongoDB without Authentication

   nohup mongo mongodb://127.0.0.1:27017/admin --quiet reIndexWithCmd.js >> reIndexWithCmd_output.log 2>&1 &

   • The execution log will be output to the reIndexWithCmd_output.log file

   MongoDB with Authentication

   nohup mongo mongodb://root:password@127.0.0.1:27017/admin --quiet reIndexWithCmd.js >> reIndexWithCmd_output.log 2>&1 &

   • If the mongo command is not in the PATH variable, you need to specify the absolute path
   • The execution log will be output to the reIndexWithCmd_output.log file

7. Monitor the log and wait for the script to complete its execution (the log will end with Process Complete and End Time)