HDC Servers

Overview

HDC (High-Density Computing) servers in the Ultipa Powerhouse (v5) architecture are the computing nodes optimized for maximum performance and efficiency.

A graph can be loaded from the physical storage of Shard servers into the memory of an HDC server, creating a HDC graph. On these HDC graphs you can execute graph queries and algorithms with enhanced performance.

Showing HDC Servers

Retrieves information about all HDC servers:

GQLUQL
SHOW HDC SERVER

Retrieves information about the HDC server named hdc-server-1:

UQL
show().hdc("hdc-server-1")

The information about HDC servers is organized into the following tables:

• _hdc: Shows the basic infomation of HDC servers, including name, addr (IP address and port of the HDC server), status (ACTIVE or DEAD), and last_heartbeat (timestamp of the last heartbeat sent to the meta servers by the HDC server).
• _hdcGraphList: Lists all HDC graphs hosted by each HDC server.

When retrieving a specific HDC server using show().hdc("<hdcServerName>"), two supplementary tables are returned:

• _hdcGraphStats: Lists all HDC graphs created on <hdcServerName> with their statistics.
• _algoList: Lists all algorithms installed on <hdcServerName>.

Adding an HDC Server

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

To add an HDC server named hdc-server-2 at 127.0.0.1:55555:

GQLUQL
ADD HDC SERVER "hdc-server-2" AT "127.0.0.1:55555"

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

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

Deleting an HDC Server

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

To delete the HDC server named hdc-server-2:

GQLUQL
REMOVE HDC SERVER "hdc-server-2"