Usage of OP logs to synchronize across primary and secondary storage clusters of a cross-site distributed storage system and lightweight OP logging

A non-transitory computer-readable storage medium embodying a set of instructions, which when executed by a processing resource of a multi-site distributed storage system cause the processing resource to:

• maintain state information regarding a data replication status for a storage object of a primary storage cluster with the storage object being replicated to a replicated storage object of a secondary storage cluster;
• temporarily disallow input/output (I/O) operations for the storage object when the storage object of the primary storage cluster has a connection loss or failure, which causes an internal state as out of sync for the storage object of the primary storage cluster while maintaining an external state as in sync for external entities in order to provide time for reestablishing synchronous replication within duration of an operation (Op) timeout period;
• perform persistent inflight tracking and reconciliation of I/O operations based on a first Op log of the primary storage cluster and a second Op log of the secondary storage cluster;
• and
• perform a resynchronization between the storage object and the replicated storage object based on the persistent inflight tracking and reconciliation of I/O operations using the first Op log of the primary storage cluster and the second Op log of the secondary storage cluster.

A multi-site distributed storage system having a primary storage site with a primary storage cluster and a secondary storage site with a secondary storage cluster, comprising:

• a processing resource;
• and
• a non-transitory computer-readable medium coupled to the processing resource, having stored therein instructions, which when executed by the processing resource cause the processing resource to:
• maintaining a first operation (Op) Log for a first volume and a second Op Log for a second volume in order to be capable of facilitating resynchronization between a dataset stored on the first volume of the primary storage cluster of the distributed storage system and a mirror copy of the dataset stored on the second volume of the secondary storage cluster of the distributed storage system, wherein changes to the dataset are synchronously replicated to the second volume;
• receive an operation associated with a file within the dataset;
• determine whether the operation is a modifying operation;
• and
• creating an operation (Op) log entry with one of the first and second Op Logs if the operation is a modifying operation to cause a modification of the file, wherein the Op log entry contains a sequence number assigned to the operation, and wherein the Op log entry is not required to contain data associated with the operation when the operation comprises a write operation.