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Prevent update if data has been updated MongoDB
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If I have a document A in mongoDB, client X and Y both retrieved A, client X send request updated A to A1, now client Y send request trying to update A to A2, what's the design pattern used in mongoDB to reject Y's request?
database mongodb
asked Jan 3 at 5:19
KunKun
1,2022917
add a comment |
If I have a document A in mongoDB, client X and Y both retrieved A, client X send request updated A to A1, now client Y send request trying to update A to A2, what's the design pattern used in mongoDB to reject Y's request?
database mongodb
asked Jan 3 at 5:19
KunKun
1,2022917
MongoDB 4 supports transactions. Have a look at them. mongodb.com/transactions
– Rajat Chaudhary
Jan 3 at 6:44
add a comment |
If I have a document A in mongoDB, client X and Y both retrieved A, client X send request updated A to A1, now client Y send request trying to update A to A2, what's the design pattern used in mongoDB to reject Y's request?
database mongodb
asked Jan 3 at 5:19
KunKun
1,2022917
If I have a document A in mongoDB, client X and Y both retrieved A, client X send request updated A to A1, now client Y send request trying to update A to A2, what's the design pattern used in mongoDB to reject Y's request?
database mongodb
database mongodb
asked Jan 3 at 5:19
KunKun
1,2022917
asked Jan 3 at 5:19
KunKun
1,2022917
asked Jan 3 at 5:19
KunKun
1,2022917
asked Jan 3 at 5:19
KunKun
1,2022917
asked Jan 3 at 5:19
KunKun
1,2022917
1,2022917
MongoDB 4 supports transactions. Have a look at them. mongodb.com/transactions
– Rajat Chaudhary
Jan 3 at 6:44
add a comment |
MongoDB 4 supports transactions. Have a look at them. mongodb.com/transactions
– Rajat Chaudhary
Jan 3 at 6:44
MongoDB 4 supports transactions. Have a look at them. mongodb.com/transactions
– Rajat Chaudhary
Jan 3 at 6:44
MongoDB 4 supports transactions. Have a look at them. mongodb.com/transactions
– Rajat Chaudhary
Jan 3 at 6:44
add a comment |
1 Answer
1
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The method you can use is called Optimistic Concurrency. Basically the idea is pretty simple, you need additional field which will represent document's version. It might be any kind of timestamp or simple number representing version.
db.col.save({ _id:1, version: 1, field: "A" })
Then both client X and Y retrieve that document. Client X updates to A1 incrementing version
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A1", version: 2 } }) // or $inc
It works since both matching conditions are fine. Then client Y tries to set A2 using the same code
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A2", version: 2 } })
But this will give you following result:
WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })
Which means that no document was modified since specified version does not match the one in the database.
Then you can handle that in your logic reloading that document for client Y or throwing some sort of concurrency exception.
answered Jan 3 at 6:42
micklmickl
15.5k51740
add a comment |
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1 Answer
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active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
The method you can use is called Optimistic Concurrency. Basically the idea is pretty simple, you need additional field which will represent document's version. It might be any kind of timestamp or simple number representing version.
db.col.save({ _id:1, version: 1, field: "A" })
Then both client X and Y retrieve that document. Client X updates to A1 incrementing version
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A1", version: 2 } }) // or $inc
It works since both matching conditions are fine. Then client Y tries to set A2 using the same code
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A2", version: 2 } })
But this will give you following result:
WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })
Which means that no document was modified since specified version does not match the one in the database.
Then you can handle that in your logic reloading that document for client Y or throwing some sort of concurrency exception.
answered Jan 3 at 6:42
micklmickl
15.5k51740
add a comment |
The method you can use is called Optimistic Concurrency. Basically the idea is pretty simple, you need additional field which will represent document's version. It might be any kind of timestamp or simple number representing version.
db.col.save({ _id:1, version: 1, field: "A" })
Then both client X and Y retrieve that document. Client X updates to A1 incrementing version
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A1", version: 2 } }) // or $inc
It works since both matching conditions are fine. Then client Y tries to set A2 using the same code
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A2", version: 2 } })
But this will give you following result:
WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })
Which means that no document was modified since specified version does not match the one in the database.
Then you can handle that in your logic reloading that document for client Y or throwing some sort of concurrency exception.
answered Jan 3 at 6:42
micklmickl
15.5k51740
add a comment |
The method you can use is called Optimistic Concurrency. Basically the idea is pretty simple, you need additional field which will represent document's version. It might be any kind of timestamp or simple number representing version.
db.col.save({ _id:1, version: 1, field: "A" })
Then both client X and Y retrieve that document. Client X updates to A1 incrementing version
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A1", version: 2 } }) // or $inc
It works since both matching conditions are fine. Then client Y tries to set A2 using the same code
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A2", version: 2 } })
But this will give you following result:
WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })
Which means that no document was modified since specified version does not match the one in the database.
Then you can handle that in your logic reloading that document for client Y or throwing some sort of concurrency exception.
answered Jan 3 at 6:42
micklmickl
15.5k51740
The method you can use is called Optimistic Concurrency. Basically the idea is pretty simple, you need additional field which will represent document's version. It might be any kind of timestamp or simple number representing version.
db.col.save({ _id:1, version: 1, field: "A" })
Then both client X and Y retrieve that document. Client X updates to A1 incrementing version
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A1", version: 2 } }) // or $inc
It works since both matching conditions are fine. Then client Y tries to set A2 using the same code
db.col.update({ _id: 1, version: 1 }, { $set: { field: "A2", version: 2 } })
But this will give you following result:
WriteResult({ "nMatched" : 0, "nUpserted" : 0, "nModified" : 0 })
Which means that no document was modified since specified version does not match the one in the database.
Then you can handle that in your logic reloading that document for client Y or throwing some sort of concurrency exception.
answered Jan 3 at 6:42
micklmickl
15.5k51740
answered Jan 3 at 6:42
micklmickl
15.5k51740
answered Jan 3 at 6:42
micklmickl
15.5k51740
answered Jan 3 at 6:42
micklmickl
15.5k51740
15.5k51740
add a comment |
add a comment |
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MongoDB 4 supports transactions. Have a look at them. mongodb.com/transactions
– Rajat Chaudhary
Jan 3 at 6:44