Cluster Transaction - Overview

• This page covers how to perform operations on a cluster-wide level through the session.

• In this page:

  • Open Cluster-Wide Session
  • Working with Compare Exchange

Open Cluster-Wide Session

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

• Sync
• Async

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

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

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

Working with Compare Exchange

Get Compare Exchange

• Sync
• Async

session.Advanced.ClusterTransaction.GetCompareExchangeValue<T>(key);

await session.Advanced.ClusterTransaction.GetCompareExchangeValueAsync<T>(key);

Parameters	Type	Description
key	string	The key to retrieve

Return Value	Description
CompareExchangeValue<T>	If the key doesn't exist it will return null

Get Multiple Values

• Sync
• Async

session.Advanced.ClusterTransaction.GetCompareExchangeValues<T>(keys);

await session.Advanced.ClusterTransaction.GetCompareExchangeValuesAsync<T>(keys);

Parameters	Type	Description
keys	string[]	Array of keys to retrieve

Return Value	Description
Dictionary<string, CompareExchangeValue<T>>	If a key doesn't exists the associate value will be null

Get Compare Exchange Lazily

• Sync
• Async

// Single value
session.Advanced.ClusterTransaction.Lazily.GetCompareExchangeValue<T>(key);

// Multiple values
session.Advanced.ClusterTransaction.Lazily.GetCompareExchangeValues<T>(keys);

// Single value
session.Advanced.ClusterTransaction.Lazily.GetCompareExchangeValueAsync<T>(key);

// Multiple values
session.Advanced.ClusterTransaction.Lazily.GetCompareExchangeValuesAsync<T>(keys);

Parameters	Type	Description
key	string	The key to retrieve
keys	string[]	Array of keys to retrieve

Return Value	Description
Lazy<CompareExchangeValue<T>>	If the key doesn't exist it will return null
Lazy<Dictionary<string, CompareExchangeValue<T>>>	If a key doesn't exists the associate value will be null

Create Compare Exchange

• Sync
• Async

session.Advanced.ClusterTransaction.CreateCompareExchangeValue(key, value);

session.Advanced.ClusterTransaction.CreateCompareExchangeValue(key, value);

Parameters	Type	Description
key	string	The key to save with the associate value. This string can be up to 512 bytes.
value	T	The value to store

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

• Sync
• Async

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

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

Delete Compare Exchange

• Sync
• Async

session.Advanced.ClusterTransaction.DeleteCompareExchangeValue(key, index);

session.Advanced.ClusterTransaction.DeleteCompareExchangeValue(key, index);

Parameters	Type	Description
key	string	The key to save with the associate value
index	long	Index for concurrency control

CompareExchangeValue

Parameters	Type	Description
key	string	Key of the item to store. This string can be up to 512 bytes.
index	long	Index for concurrency control
value	T	The actual value to keep