Management of logs and cache for a graph database
Systems, methods, and software described herein manage logs and cache storage for a graph database. In one implementation, a replica in a cluster of replicas, identifies an update associated with a graph database. In response to the update, the first replica determines whether a quorum exists for the update using one or more additional replicas and, when a quorum exists, generates an entry in a log based on the update.
1 . A method comprising:
in a first replica, identifying an update associated with a graph database;
verifying a signature provided to the first replica in association with the update;
in the first replica and in response to verifying the signature, determining a quorum of one or more additional replicas have verified the signature;
in the first replica and in response to determining the quorum, generating an entry for the update in a log of entries for updates to the graph database; and
in response to a synchronization event, updating a local snapshot of the graph database at the first replica using the entries from the log.
2 . The method of claim 1 , wherein the update comprises an addition, deletion, or modification to a vertex or edge in the graph database.
3 . The method of claim 1 further comprising:
in the first replica, identifying the synchronization event for the graph database; and
in the first replica and in response to the synchronization event, communicating one or more entries from the log to a cloud data store that stores the graph database.
4 . The method of claim 3 , wherein the synchronization event comprises a quantity of entries in the log satisfying a threshold, an expiration of a period, or resource usage of the first replica satisfying one or more criteria.
5 . The method of claim 1 , wherein the signature is created by signing the update with a first encryption key and wherein the first replica and the quorum of the one or more additional replicas verify the signature using a second encryption key.
6 . The method of claim 1 further comprising, in the first replica, maintaining the local snapshot of the graph database.
7 . The method of claim 6 further comprising:
in the first replica, identifying a query to the graph database; and
in the first replica and in response to the query, generating a query response based on the local snapshot and the log.
8 . The method of claim 1 further comprising:
in the first replica, identifying a second update associated with the graph database;
verifying a second signature provided to the first replica in association with the second update;
in the first replica and in response to verifying the second signature, determining a second quorum of the one or more additional replicas does not exist; and
in the first replica and in response to determining the second quorum does not exist, preventing the second update from being applied in the log.
9 . The method of claim 1 further comprising:
in the one or more additional replicas, identifying a failure of the first replica; and
in the one or more additional replicas and in response to identifying the failure of the first replica, selecting a second replica in the one or more additional replicas to replace the first replica as a leader.
10 . A computing apparatus comprising:
a storage system;
a processing system operatively coupled to the storage system; and
program instructions stored on the storage system to operate a first replica in a cluster that, when executed by the processing system, direct the computing apparatus to:
identify an update associated with a graph database;
verify a signature provided to the first replica in association with the update;
in response to verifying the signature, determine a quorum of one or more additional replicas in the cluster have verified the signature;
in response to determining the quorum, generate an entry for the update in a log of entries for updates to the graph database; and
in response to a synchronization event, update a snapshot of the graph database at the first replica using the entries from the log.
11 . The computing apparatus of claim 10 , wherein the update comprises an addition, deletion, or modification to a vertex or edge in the graph database.
12 . The computing apparatus of claim 10 , wherein the program instructions further direct the computing apparatus to:
identify the synchronization event for the graph database; and
in response to the synchronization event, communicate one or more entries from the log to a cloud store that stores the graph database.
13 . The computing apparatus of claim 12 , wherein the synchronization event comprises a quantity of entries in the log satisfying a threshold, an expiration of a period, or resource usage of the first replica satisfying one or more criteria.
14 . The computing apparatus of claim 10 , wherein the signature is created by signing the update with a first encryption key and wherein the first replica and the quorum of the one or more additional replicas verify the signature using a second encryption key.
15 . The computing apparatus of claim 10 , wherein the program instructions further direct the computing apparatus to maintain a snapshot comprising frequently accessed data in association with the graph database.
16 . The computing apparatus of claim 15 , wherein the program instructions further direct the computing apparatus to:
identify a query to the graph database; and
generate a query response based on the snapshot and the log.
17 . The computing apparatus of claim 10 , wherein the program instructions further direct the computing apparatus to:
identify a second update associated with the graph database;
verify a second signature provided to the first replica in association with the second update;
in response to verifying the second signature, determine a second quorum of the one or more additional replicas does not exist; and
in response to determining the second quorum does not exist, prevent the second update from being applied in the log.
18 . A system comprising:
a plurality of replicas, wherein each replica comprises at least one computer; and
a first replica in the plurality of replicas configured to:
identify an update associated with a graph database;
verify a signature provided to the first replica in association with the update;
in response to verifying the signature, determine a quorum of one or more additional replicas in the plurality of replicas have verified the signature;
in response to determining the quorum, generate an entry for the update in a log of entries for updates to the graph database; and
in response to a synchronization event, update a snapshot of the graph database at the first replica using the entries from the log.
19 . The system of claim 18 , wherein the first replica is further configured to:
identify the synchronization event for the graph database; and
communicate one or more entries from the log to a cloud data store that stores the graph database.
20 . The system of claim 18 , wherein one or more replicas of the plurality of replicas are configured to:
identify a failure of the first replica; and
in response to identifying the failure of the first replica, select a second replica in the one or more replicas to replace the first replica as a leader, wherein the leader updates snapshots in a cloud data store.