8.3.9. Resource Quota Options
The maximum number of connections can be restricted with the
--max-connections broker option.
Table 8.8. Resource Quota Options
| Option | Description | Default Value |
|---|---|---|
--max-connections N
|
Total concurrent connections to the broker.
|
500
|
--max-negotiate-time N
|
The time during which initial protocol negotiation must succeed. This prevents resource starvation by badly behaved clients or transient network issues that prevent connections from completing.
|
500
|
Notes
--max-connectionsis a qpid core limit and is enforced whether ACL is enabled or not.--max-connectionsis enforced per Broker. In a cluster of N nodes where all Brokers set the maximum connections to 20 the total number of allowed connections for the cluster will be N*20.
ACL-based Quotas
To enable ACL-based quotas, an ACL file must be loaded:
Table 8.9. ACL Command-line Option
| Option | Description | Default Value |
|---|---|---|
--acl-file FILE (policy.acl)
|
The policy file to load from, loaded from data dir.
|
When an ACL file is loaded, the following ACL options can be specified at the command-line to enforce resource quotas:
Table 8.10. ACL-based Resource Quota Options
|
Option
| Description | Default Value |
|---|---|---|
--connection-limit-per-user N
|
The maximum number of connections allowed per user. 0 implies no limit.
|
0
|
--connection-limit-per-ip N
|
The maximum number of connections allowed per host IP address. 0 implies no limit.
| 0 |
--max-queues-per-user N
|
Total concurrent queues created by individual user
|
0
|
Notes
- In a cluster system the actual number of connections may exceed the connection quota value
Nby one less than the number of member nodes in the cluster. For example: in a 5-node cluster, with a limit of 20 connections, the actual number of connections can reach 24 before limiting takes place. - Cluster connections are checked against the connection limit when they are established. The cluster connection is denied if a free connection is not available. After establishment, however, a cluster connection does not consume a connection.
- Allowed values for
Nare 0..65535. - These limits are enforced per cluster.
- A value of zero (0) disables that option's limit checking.
- Per-user connections are identified by the authenticated user name.
- Per-ip connections are identified by the
<broker-ip><broker-port>-<client-ip><client-port>tuple which is also the management connection index.- With this scheme host systems may be identified by several names such as
localhostIPv4,127.0.0.1IPv4, or::1IPv6, and a separate set of connections is allowed for each name. - Per-IP connections are counted regardless of the user credentials provided with the connections. An individual user may be allowed 20 connections but if the client host has a 5 connection limit then that user may connect from that system only 5 times.
