# Proxy Type Selection

Distributed Redis currently creates pages that support two types of proxy configuration modes: master-replica and load balancing proxies.

## master-replica Proxy

### Characteristics
The master-replica proxy ensures the high availability of the proxy service through the master-replica mode. Users can choose to add or delete proxies and expand or reduce proxies according to the usage of the proxy to achieve elastic expansion. After the master-replica proxy is added, Distributed Redis will provide an additional IP entrance, allowing users to allocate proxy entrance services based on business attributes.

### Expansion
On the proxy management page, users can add and expand proxies for expansion.
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### Note
- When deleting the master-replica proxy, please ensure that the business is not using this proxy.


## Load Balancing Proxy

### Characteristics
The load-balancing proxy adopts the ULB4+Proxy architecture for message forwarding. The Proxy serves as the RServer node. Users access the ULB4 entrance, and requests are distributed to the proxy node according to the load-balancing strategy. Each proxy node operates in a single-point mode. When a node fails, ULB4 will actively disconnect the node immediately, and requests will be forwarded to the normal service proxy node.

### Expansion
Under the load-balancing proxy mode, horizontal and vertical expansions are also supported on the proxy management page.

### Note
- The load balancing proxy must ensure that at least two proxy nodes exist.
- Currently, only distributed clusters can choose to configure load balancing proxies when created 
- For performance indicators of message forwarding ULB4, refer [here](/docs/ulb/clb/intro/performance)


## Comparison of Modes

- The master-replica proxy provides multiple IP service entrances by adding, requiring active adjustments to the business needs; in contrast, the load balancing proxy mode unifies the IP entrance, implicitly completing the expansion without requiring business adjustments.
- The expansion of the load balancing proxy is limited by the performance of the message forwarding ULB4, whereas the master-replica proxy is not subject to such restrictions.
- Request allocation for the load balancing proxy primarily relies on ULB4’s message forwarding strategy, while requests for the master-replica proxy can be configured by the user based on actual business needs.
- All proxy nodes in the load balancing proxy operate in single-point mode, meaning that as the number of proxies increases, costs decrease, making the load balancing proxy more cost-effective.
- Because requests from the client are forwarded to the proxy node through ULB4 in the load balancing proxy, there may be an increase in latency.