Revert "SERVER-78950 Use sequential time series bucket IDs when possible"r7.0.0-rc10

This reverts commit e8662106357ca486ac26252562058a796ad2403e.

4 files changed, 7 insertions, 32 deletions

diff --git a/src/mongo/db/timeseries/bucket_catalog/bucket_catalog.cpp b/src/mongo/db/timeseries/bucket_catalog/bucket_catalog.cpp
index 0868b9264a1..22a1ba0abba 100644
--- a/src/mongo/db/timeseries/bucket_catalog/bucket_catalog.cpp
+++ b/src/mongo/db/timeseries/bucket_catalog/bucket_catalog.cpp
@@ -369,10 +369,6 @@ void clear(BucketCatalog& catalog, StringData dbName) {
     });
 }
 
-void resetBucketOIDCounter() {
-    internal::resetBucketOIDCounter();
-}
-
 void appendExecutionStats(const BucketCatalog& catalog,
                           const NamespaceString& ns,
                           BSONObjBuilder& builder) {
diff --git a/src/mongo/db/timeseries/bucket_catalog/bucket_catalog.h b/src/mongo/db/timeseries/bucket_catalog/bucket_catalog.h
index 141c13d334b..b66a7c4e264 100644
--- a/src/mongo/db/timeseries/bucket_catalog/bucket_catalog.h
+++ b/src/mongo/db/timeseries/bucket_catalog/bucket_catalog.h
@@ -266,11 +266,6 @@ void clear(BucketCatalog& catalog, const NamespaceString& ns);
 void clear(BucketCatalog& catalog, StringData dbName);
 
 /**
- * Resets the counter used for bucket OID generation. Should be called after a bucket _id collision.
- */
-void resetBucketOIDCounter();
-
-/**
  * Appends the execution stats for the given namespace to the builder.
  */
 void appendExecutionStats(const BucketCatalog& catalog,
diff --git a/src/mongo/db/timeseries/bucket_catalog/bucket_catalog_internal.cpp b/src/mongo/db/timeseries/bucket_catalog/bucket_catalog_internal.cpp
index 53d46946fe0..a61a1ed17f2 100644
--- a/src/mongo/db/timeseries/bucket_catalog/bucket_catalog_internal.cpp
+++ b/src/mongo/db/timeseries/bucket_catalog/bucket_catalog_internal.cpp
@@ -47,7 +47,6 @@ MONGO_FAIL_POINT_DEFINE(hangWaitingForConflictingPreparedBatch);
 Mutex _bucketIdGenLock =
     MONGO_MAKE_LATCH(HierarchicalAcquisitionLevel(0), "bucket_catalog_internal::_bucketIdGenLock");
 PseudoRandom _bucketIdGenPRNG(SecureRandom().nextInt64());
-AtomicWord<uint64_t> _bucketIdGenCounter{static_cast<uint64_t>(_bucketIdGenPRNG.nextInt64())};
 
 OperationId getOpId(OperationContext* opCtx, CombineWithInsertsFromOtherClients combine) {
     switch (combine) {
@@ -1088,28 +1087,21 @@ std::pair<OID, Date_t> generateBucketOID(const Date_t& time, const TimeseriesOpt
     // paradox converges to roughly the square root of the size of the space, so we would need a few
     // billion buckets with the same timestamp to expect collisions. In the rare case that we do get
     // a collision, we can (and do) simply regenerate the bucket _id at a higher level.
-    uint64_t bits = BigEndian<uint64_t>::store(_bucketIdGenCounter.addAndFetch(1));
-
     OID::InstanceUnique instance;
-    const auto instanceBuf = static_cast<uint8_t*>(instance.bytes);
-    std::memcpy(instanceBuf, &bits, OID::kInstanceUniqueSize);
-
     OID::Increment increment;
-    const auto incrementBuf = static_cast<uint8_t*>(increment.bytes);
-    uint8_t* bitsBuf = (uint8_t*)&bits;
-    std::memcpy(incrementBuf, &(bitsBuf)[OID::kInstanceUniqueSize], OID::kIncrementSize);
-
+    {
+        // We need to serialize access to '_bucketIdGenPRNG' since this instance is shared between
+        // all bucket_catalog operations, and not protected by the catalog or stripe locks.
+        stdx::unique_lock lk{_bucketIdGenLock};
+        _bucketIdGenPRNG.fill(instance.bytes, OID::kInstanceUniqueSize);
+        _bucketIdGenPRNG.fill(increment.bytes, OID::kIncrementSize);
+    }
     oid.setInstanceUnique(instance);
     oid.setIncrement(increment);
 
     return {oid, roundedTime};
 }
 
-void resetBucketOIDCounter() {
-    stdx::lock_guard lk{_bucketIdGenLock};
-    _bucketIdGenCounter.store(static_cast<uint64_t>(_bucketIdGenPRNG.nextInt64()));
-}
-
 Bucket& allocateBucket(BucketCatalog& catalog,
                        Stripe& stripe,
                        WithLock stripeLock,
@@ -1134,9 +1126,6 @@ Bucket& allocateBucket(BucketCatalog& catalog,
                                      info.options.getTimeField(),
                                      roundedTime,
                                      catalog.bucketStateRegistry));
-        if (!inserted) {
-            resetBucketOIDCounter();
-        }
     }
     uassert(6130900,
             "Unable to insert documents due to internal OID generation collision. Increase the "
diff --git a/src/mongo/db/timeseries/bucket_catalog/bucket_catalog_internal.h b/src/mongo/db/timeseries/bucket_catalog/bucket_catalog_internal.h
index 99f6169a1a9..ff3a6e9121e 100644
--- a/src/mongo/db/timeseries/bucket_catalog/bucket_catalog_internal.h
+++ b/src/mongo/db/timeseries/bucket_catalog/bucket_catalog_internal.h
@@ -295,11 +295,6 @@ void expireIdleBuckets(BucketCatalog& catalog,
 std::pair<OID, Date_t> generateBucketOID(const Date_t& time, const TimeseriesOptions& options);
 
 /**
- * Resets the counter used for bucket OID generation. Should be called after a collision.
- */
-void resetBucketOIDCounter();
-
-/**
  * Allocates a new bucket and adds it to the catalog.
  */
 Bucket& allocateBucket(BucketCatalog& catalog,