My WebSocket connections drop after a certain time; what should I do?

Short answer

After a WebSocket connection is established, TR7 carries it as a tunnel; if no data passes in either direction, the connection closes when the Tunnel(Websocket) Timeout in the Timeouts profile (default 120 seconds) runs out. In the tunnel, Client Timeout and Server Timeout are not decisive. The solution is to create a Timeouts profile whose Tunnel(Websocket) timeout value is greater than the ping/pong interval of the application and assign it to the vService; sending pings on the application side at intervals shorter than this duration also keeps the connection open (WebSocket and long-lived connections).

Problem: Idle WebSocket Connections Drop

In applications such as notifications, chat or live dashboards, the WebSocket connection stays open for a long time without carrying data. If the connections always drop after the same duration and the client has to reconnect, the idle time limit is running out. The reason for the dropped connection is seen in the Termination State column on the Debug Mode Logs screen while the HTTP vService is in Debug mode.

Solution: Three Methods

Your situation	Suitable method
Increasing the tunnel duration from the interface	Method 1: Tunnel(Websocket) timeout profile
The application can send pings	Method 2: Application-side ping/pong
From the command line	Method 3: WEB-CLI

Method 1: Tunnel(Websocket) Timeout Profile Recommended

• How it works The time the connection in tunnel state can stay idle is increased.
• Where it is openedLoad Balancer → Profiles → Timeouts · vService → Details → Timeout
• Requirement The ping/pong interval of the application must be known
• vService type HTTP · L7 TCP (on L7 TCP, HTTP Keepalive Timeout and HTTP Request Timeout are not used)

Step-by-Step Configuration

1

Adım 1 Open the profile form

Load Balancer → Profiles → Timeouts → Add is clicked (how to add). A separate profile is recommended for WebSocket (operational best practices).

2

Adım 2 Enter the name

The profile name is written in the Name field (e.g. websocket-servisi).

3

Adım 3 Increase the tunnel duration

Tunnel(Websocket) Timeout is set to a value greater than the ping/pong interval of the application (e.g. 3600). The values are in seconds (0–60,000); fields left empty use the default.

4

Adım 4 Save the profile

Add is clicked.

5

Adım 5 Select the profile on the vService

Load Balancer → Load Balancer vService List → vService → Edit; in the Details panel, the Timeout box is checked and the profile is selected from the list (how to add to a vService).

6

Adım 6 Save

Save is clicked. Timeouts changes are applied without dropping open connections. In a cluster, it is also sent to the peer device with the default auto-sync; if Manual Sync Mode is on, it is sent with Synchronize.

Verification

1DurationClient side

A WebSocket connection is opened and kept waiting without sending data for a period longer than the old duration and shorter than the new duration.

ExpectedThe connection stays open

Method 2: Application-Side Ping/Pong

• How it works When the application sends pings at regular intervals, the connection is not considered idle and the tunnel duration does not run out.
• Where it is opened The WebSocket settings of the application (client or server)
• Requirement Ping/pong support in the application
• vService type HTTP · L7 TCP

Step-by-Step Configuration

1

Adım 1 Set the interval

The ping interval of the application is kept shorter than the Tunnel(Websocket) timeout value (e.g. 30 seconds for a duration of 120 seconds).

Verification

1DurationClient side

A WebSocket connection is opened and kept waiting without sending application data for longer than the Tunnel(Websocket) timeout duration.

ExpectedThe connection stays open

Method 3: WEB-CLI

• How it works The profile is created from the command line and bound to the vService.
• Where it is opened TR7 WEB-CLI → lb timeouts · lb service
• Requirement WEB-CLI access
• vService type HTTP · L7 TCP

Step-by-Step Configuration

1

Adım 1 Create the profile

The value is in seconds (Timeouts examples):

lb timeouts add name websocket-servisi --tunnelTimeout 3600

2

Adım 2 Bind the profile to the vService

lb service update id <vService> --timeout websocket-servisi

Verification

1DurationClient side

A WebSocket connection is opened and kept waiting without sending data for a period longer than the old duration and shorter than the new duration.

ExpectedThe connection stays open

Common Mistakes

• Increasing the Client and Server timeout. After the tunnel is established, the decisive duration is the Tunnel(Websocket) timeout.
• Keeping the duration shorter than the ping interval. If no ping arrives before the tunnel duration expires, the connection drops; the tunnel duration is chosen longer than the ping interval.
• Mistaking a connection failure for a drop. If many concurrent WebSockets reach the Max. Total Connections limit (default 20,000) in the vService Limits profile, or the Max. Total SSL Connections limit (default 5,000) for wss://, new connections wait; existing connections do not drop (What happens when the connection limit is reached?).
• Overlooking the WebSocket setup. For the vService type and the Upgrade verification: Can I load balance WebSocket traffic?

How it is done in the documentation

• Timeouts · Tunnel(Websocket) Timeout
• Timeouts · WebSocket and the Long-Lived Connections
• WEB-CLI · Examples

Related questions

• Can I load balance WebSocket traffic?
• What do the values in the Timeouts profile (HTTP Keepalive Timeout, HTTP Request Timeout, Connect, Server, Client, Queue, Tunnel(Websocket) Timeout, Client FIN, Server FIN) mean?
• Why is the request cut off during long operations (report, file upload); which timeout should I increase?