SERVER-35627 Repair should recreate missing collection data files with the existing metadata.

1 files changed, 154 insertions, 0 deletions

diff --git a/jstests/disk/wt_repair_missing_files.js b/jstests/disk/wt_repair_missing_files.js
new file mode 100644
index 00000000000..c0273f7b647
--- /dev/null
+++ b/jstests/disk/wt_repair_missing_files.js
@@ -0,0 +1,154 @@
+/**
+ * Tests that --repair on WiredTiger correctly and gracefully handles missing data files and
+ * directories.
+ *
+ * @tags: [requires_wiredtiger]
+ */
+
+(function() {
+
+    const baseName = "wt_repair_missing_files";
+    const collName = "test";
+    const dbpath = MongoRunner.dataPath + baseName + "/";
+
+    resetDbpath(dbpath);
+
+    let getUriForColl = function(coll) {
+        let ret = coll.stats();
+        assert.commandWorked(ret);
+        let uri = ret.wiredTiger.uri.split("table:")[1];
+        assert.neq(typeof(uri), 'undefined');
+        return uri;
+    };
+
+    let getUriForIndex = function(coll, indexName) {
+        let ret = coll.getDB().runCommand({collStats: coll.getName()});
+        assert.commandWorked(ret);
+
+        let uri = ret.indexDetails[indexName].uri.split("table:")[1];
+        assert.neq(typeof(uri), 'undefined');
+        return uri;
+    };
+
+    /**
+     * Test 1. Create a collection, delete it's .wt file, run repair. Verify that repair succeeds at
+     * re-creating it. The collection should be visible on normal startup.
+     */
+
+    let mongod = MongoRunner.runMongod({dbpath: dbpath});
+    let testColl = mongod.getDB(baseName)[collName];
+
+    const doc = {a: 1};
+    assert.writeOK(testColl.insert(doc));
+
+    let testCollUri = getUriForColl(testColl);
+    let testCollFile = dbpath + testCollUri + ".wt";
+
+    MongoRunner.stopMongod(mongod);
+
+    jsTestLog("deleting collection file: " + testCollFile);
+    removeFile(testCollFile);
+
+    assert.eq(0, runMongoProgram("mongod", "--repair", "--port", mongod.port, "--dbpath", dbpath));
+
+    mongod = MongoRunner.runMongod({dbpath: dbpath, noCleanData: true});
+    testColl = mongod.getDB(baseName)[collName];
+
+    assert.eq(testCollUri, getUriForColl(testColl));
+    assert.eq(testColl.find({}).itcount(), 0);
+    assert.eq(testColl.count(), 0);
+
+    /**
+     * Test 2. Delete an index file. Verify that repair rebuilds and allows MongoDB to start up
+     * normally.
+     */
+
+    let assertQueryUsesIndex = function(coll, query, indexName) {
+        let res = coll.find(query).explain();
+        assert.commandWorked(res);
+
+        let inputStage = res.queryPlanner.winningPlan.inputStage;
+        assert.eq(inputStage.stage, "IXSCAN");
+        assert.eq(inputStage.indexName, indexName);
+    };
+
+    assert.writeOK(testColl.insert(doc));
+
+    const indexName = "a_1";
+    assert.commandWorked(testColl.createIndex({a: 1}, {name: indexName}));
+    assertQueryUsesIndex(testColl, doc, indexName);
+
+    let indexUri = getUriForIndex(testColl, indexName);
+
+    MongoRunner.stopMongod(mongod);
+
+    let indexFile = dbpath + indexUri + ".wt";
+    jsTestLog("deleting index file: " + indexFile);
+    removeFile(indexFile);
+
+    assert.eq(0, runMongoProgram("mongod", "--repair", "--port", mongod.port, "--dbpath", dbpath));
+    mongod = MongoRunner.runMongod({dbpath: dbpath, noCleanData: true});
+    testColl = mongod.getDB(baseName)[collName];
+
+    // Repair creates new idents.
+    assert.neq(indexUri, getUriForIndex(testColl, indexName));
+
+    assertQueryUsesIndex(testColl, doc, indexName);
+    assert.eq(testColl.find(doc).itcount(), 1);
+    assert.eq(testColl.count(), 1);
+
+    MongoRunner.stopMongod(mongod);
+
+    /**
+     * Test 3. Delete the _mdb_catalog. Verify that repair suceeds in creating an empty catalog and
+     * MongoDB starts up normally with no data.
+     */
+
+    let mdbCatalogFile = dbpath + "_mdb_catalog.wt";
+    jsTestLog("deleting catalog file: " + mdbCatalogFile);
+    removeFile(mdbCatalogFile);
+
+    assert.eq(0, runMongoProgram("mongod", "--repair", "--port", mongod.port, "--dbpath", dbpath));
+
+    mongod = MongoRunner.runMongod({dbpath: dbpath, noCleanData: true});
+    testColl = mongod.getDB(baseName)[collName];
+    assert.commandFailed(testColl.stats());
+
+    assert.eq(testColl.find(doc).itcount(), 0);
+    assert.eq(testColl.count(), 0);
+
+    /**
+     * Test 4. Verify that using repair with --directoryperdb creates a missing directory and its
+     * files, allowing MongoDB to start up normally.
+     */
+
+    MongoRunner.stopMongod(mongod);
+    resetDbpath(dbpath);
+
+    mongod = MongoRunner.runMongod({dbpath: dbpath, directoryperdb: "", noCleanData: true});
+    testColl = mongod.getDB(baseName)[collName];
+
+    assert.writeOK(testColl.insert(doc));
+
+    testCollUri = getUriForColl(testColl);
+
+    MongoRunner.stopMongod(mongod);
+
+    let dataDir = dbpath + baseName;
+    jsTestLog("deleting data directory: " + dataDir);
+    removeFile(dataDir);
+
+    assert.eq(
+        0,
+        runMongoProgram(
+            "mongod", "--repair", "--directoryperdb", "--port", mongod.port, "--dbpath", dbpath));
+
+    mongod = MongoRunner.runMongod({dbpath: dbpath, directoryperdb: "", noCleanData: true});
+    testColl = mongod.getDB(baseName)[collName];
+
+    assert.eq(testCollUri, getUriForColl(testColl));
+    assert.eq(testColl.find({}).itcount(), 0);
+    assert.eq(testColl.count(), 0);
+
+    MongoRunner.stopMongod(mongod);
+})();