Shard Servers

Overview

Shard servers are a crucial component of the Ultipa Powerhouse (v5) architecture, typically comprising multiple servers dedicated to distributed graph storage and computation. This design enables horizontal scaling while delivering highly competitive performance.

Each shard supports multi-replica data storage. In the three-shard setup example below, shards 1 and 2 each have three replicas, while shard 3 has two replicas. Graphs are distributed across these shards: Graph_1 in all three shards, Graph_2 and Graph_3 partially stored across the three shards, and Graph_4 located in a single shard.

Showing Shard Servers

Retrieves information about all shard servers:

UQL
show().shard()

The details returned for each shard server include:

Adding a Shard Server

After successfully deploying a new shard server, it must be registered with the meta servers before it can be utilized. This process ensures that the new shard server is recognized within the system.

Adds a Shard server 4 with three replicas:

UQL
alter().shard().add({
  shardId: 4,
  replicas: [
    {addr: "127.0.0.1:40061", streamAddr: "127.0.0.1:40023"},
    {addr: "127.0.0.2:40061", streamAddr: "127.0.0.2:40023"},
    {addr: "127.0.0.3:40061", streamAddr: "127.0.0.3:40023"}
  ]
})

You can also add shard servers on the server-side by running the ./ultipa.sh script provided during deployment:

Bash
./ultipa.sh cluster addshard --config example.sh

Altering a Shard Server

You can alter the replicas of a shard server.

Alters the replicas of the Shard server 4:

UQL
alter().shard().replace({
  shardId: 4,
  replicas: [
    {addr: "127.0.0.1:40061", streamAddr: "127.0.0.1:40023"},
    {addr: "127.0.0.2:40061", streamAddr: "127.0.0.2:40023"}
  ]
})

Deleting a Shard Server

You can unregister an inactive or obsolete shard server from the meta servers.

Deletes the shard server 1:

UQL
alter().shard().delete({shardId: 1})