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Cluster Transaction - Overview

Open Cluster-Wide Session​

To open cluster transaction session you have to set the TransactionMode to TransactionMode.ClusterWide.

using (var session = store.OpenSession(new SessionOptions
{
  TransactionMode = TransactionMode.ClusterWide
}))

You can store, delete and edit document and the session will track them as usual.

Working with Compare Exchange​

Get Compare Exchange​

session.Advanced.ClusterTransaction.GetCompareExchangeValue<T>(key);
Parameters
keystringThe key to retrieve
Return Value
CompareExchangeValue<T>If the key doesn't exists it will return null
session.Advanced.ClusterTransaction.GetCompareExchangeValues<T>(keys);
Parameters
keysstring[]Array of keys to retrieve
Return Value
Dictionary<string, CompareExchangeValue<T>>If a key doesn't exists the associate value will be null

Create Compare Exchange​

session.Advanced.ClusterTransaction.CreateCompareExchangeValue(key, value);
Parameters
keystringThe key to save with the associate value. This string can be up to 512 bytes.
valueTThe value to store

If the value is already exists SaveChanges() will throw a ConcurrencyException.

// occupy "Best NoSQL Transactional Database" to be "RavenDB"
session.Advanced.ClusterTransaction.CreateCompareExchangeValue(key: "Best NoSQL Transactional Database", value: "RavenDB");
session.SaveChanges();

Update Compare Exchange​

session.Advanced.ClusterTransaction.UpdateCompareExchangeValue(new CompareExchangeValue<T>(key, index, value));
Parameters
itemCompareExchangeValue<T>The item to update

If the value was changed by someone else the SaveChanges() will throw a ConcurrencyException.

_async
                  // load the existing dns record of ravendb.net
                  CompareExchangeValue<DNS> result = await session.Advanced.ClusterTransaction.GetCompareExchangeValueAsync<DNS>(key: "ravendb.net");

                  // change the ip
                  result.Value.IpAddress = "52.32.173.150";
                  session.Advanced.ClusterTransaction.UpdateCompareExchangeValue(result);
                  
                  // save the changes
                  await session.SaveChangesAsync();

Delete Compare Exchange​

session.Advanced.ClusterTransaction.DeleteCompareExchangeValue(key, index);
Parameters
keystringThe key to save with the associate value
indexlongIndex for concurrency control

CompareExchangeValue​

Parameters
keystringKey of the item to store. This string can be up to 512 bytes.
indexlongIndex for concurrency control
valueTThe actual value to keep