Abstract: Systems and methods for enforcing consistency of file to storage node mappings in distributed file systems. An example method may include: receiving a request to perform a file operation with respect to a file associated with a directory of a distributed file system; identifying a directory layout version number associated with the directory; identifying a volume layout version number associated with a volume in which the directory resides; and responsive to determining that the directory layout version number matches the volume layout version number, performing the requested file operation with respect to the file.

Abstract: A request to store a file in a directory of a volume associated with a distributed file system may be received. A server of a plurality of servers of the distributed file system that is associated with the file may be identified. A first version number associated with the directory and a second version number associated with the volume may be compared. The file may be stored in the directory at the identified server when the first version number matches the second version number and when the file is not currently stored at the server.

Abstract: Systems and methods for allocating file system metadata to storage nodes of a distributed file system. An example method may include: defining, by a processing device, a plurality of tokens, wherein each token comprises a sequence of bits; associating each token of the plurality of tokens with a metadata node of a cluster of metadata nodes; receiving a request to create a directory; selecting, among the plurality of tokens, a token associated with the directory; generating a directory identifier comprising the selected token; and creating, on a metadata node associated with the selected token, a directory record comprising the directory identifier.

Abstract: Replication in a distributed file system is described. A processing device determines that a completion threshold has been satisfied in view of at least a received indication of completion of a new data modification request, wherein the completion threshold comprises a number of server devices of the distributed file system for which the new data modification has been performed thereon. The processing device provides, in response to determining that the completion threshold has been satisfied, a message to a client device that the new data modification request was performed successfully.

Abstract: A file may be identified and a plurality of rules associated with a plurality of storage servers may be received. An order for the rules may be identified. A particular storage server of the plurality of storage servers that satisfies a condition for each of the rules in view of the order for the rules and a characteristic associated with each of the plurality of storage servers. The file may be stored at the particular storage server that satisfies the condition for each of the rules.

Abstract: Systems and methods for enforcing consistency of file to storage node mappings in distributed file systems. An example method may include: receiving a request to perform a file operation with respect to a file associated with a directory of a distributed file system; identifying a directory layout version number associated with the directory; identifying a volume layout version number associated with a volume in which the directory resides; and responsive to determining that the directory layout version number matches the volume layout version number, performing the requested file operation with respect to the file.

Abstract: Systems and methods for enforcing consistency of file to storage node mappings in distributed file systems. An example method may include: receiving a request to perform a file operation with respect to a file associated with a volume of a distributed file system; identifying, among a plurality of storage nodes of the distributed file system, a storage node associated with the file; obtaining a lock of a layout of the volume; and responsive to determining, by a processing device, that a directory layout version number matches a volume layout version number, performing the requested file operation with respect to the file.

Abstract: Replication in a distributed file system is described. A processing device determines that a completion threshold has been satisfied in view of at least a received indication of completion of a new data modification request, wherein the completion threshold comprises a number of server devices of the distributed file system for which the new data modification has been performed thereon. The processing device provides, in response to determining that the completion threshold has been satisfied, a message to a client device that the new data modification request was performed successfully.

Abstract: Replication in a distributed file system is described. A processing device receives a new data modification request from a client device. The processing device provides the request in a sequence to a server. The server is to perform the new data modification request in view of the sequence. The processing device receives an indication of completion of the new data modification request from the server. The processing device determines that a completion threshold has been satisfied in view of the received indication of completion of the new data modification request. The processing device provides, in view of the determining, a message to the client device that the new data modification request was performed successfully.

Abstract: Systems and methods for indexing and searching an event log to determine whether an object of a file system is current. An example method may comprise: arranging a plurality of events into multiple segments, the plurality of events comprising operations affecting a plurality of objects; generating multiple indexes in view of the one or more segments, the indexes comprising a composite index representing the plurality of objects modified by the plurality of events; and inspecting the composite index to determine an object of the plurality of objects is modified by at least one of the plurality of events.

Abstract: Systems and methods for enforcing consistency of file to storage node mappings in distributed file systems. An example method may include: receiving a request to perform a file operation with respect to a file associated with a volume of a distributed file system; identifying, among a plurality of storage nodes of the distributed file system, a storage node associated with the file; obtaining a lock of a layout of the volume; and responsive to determining, by a processing device, that a directory layout version number matches a volume layout version number, performing the requested file operation with respect to the file.

Abstract: Systems and methods for allocating file system metadata to storage nodes of a distributed file system. An example method may include: defining, by a processing device, a plurality of tokens, wherein each token comprises a sequence of bits; associating each token of the plurality of tokens with a metadata node of a cluster of metadata nodes; receiving a request to create a directory; selecting, among the plurality of tokens, a token associated with the directory; generating a directory identifier comprising the selected token; and creating, on a metadata node associated with the selected token, a directory record comprising the directory identifier.

Abstract: A request to store a file in a directory of a volume associated with a distributed file system may be received. A server of a plurality of servers of the distributed file system that is associated with the file may be identified. A first version number associated with the directory and a second version number associated with the volume may be compared. The file may be stored in the directory at the identified server when the first version number matches the second version number and when the file is not currently stored at the server.

Abstract: Replication in a distributed file system is described. A processing device receives a new data modification request from a client device. The processing device provides the request in a sequence to a server. The server is to perform the new data modification request in view of the sequence. The processing device receives an indication of completion of the new data modification request from the server. The processing device determines that a completion threshold has been satisfied in view of the received indication of completion of the new data modification request. The processing device provides, in view of the determining, a message to the client device that the new data modification request was performed successfully.

Abstract: A file may be identified and a plurality of rules associated with a plurality of storage servers may be received. An order for the rules may be identified. A particular storage server of the plurality of storage servers that satisfies a condition for each of the rules in view of the order for the rules and a characteristic associated with each of the plurality of storage servers. The file may be stored at the particular storage server that satisfies the condition for each of the rules.

Abstract: File locks and file metadata are distributed from a file manager to clients in a data network to permit the clients to share access to file data in data storage. The file manager is permitted to grant a second lock upon the file data without necessarily receiving notification from a client that it has relinquished a first lock on the file data while ensuring that conflicting locks are never granted. The client sets the beginning of a first period of time over which the client may access the file data once the first lock on the file data has been granted by the file manager, and the client sends a lock request to the file manager. The file manager responds by setting the beginning of a second period of time such that the first period of time is certain to have expired once the second period of time has expired, granting the first lock upon the file data to the client, and transmitting a lock grant message to the client.