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‎docs/cluster-formation.md

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@@ -307,6 +307,10 @@ Podman is one known example of a tool that can perform such host file modificati
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In order to avoid this, set its [`host_containers_internal_ip` setting](https://github.com/containers/common/blob/main/docs/containers.conf.5.md)
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must be set to a blank string.
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In environments where container-level settings cannot be tuned, the runtime
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can be [configured to ignore the standard local hosts file](./networking#the-inetrc-file)
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and only use DNS or a pre-configured set of hostname-to-IP address mappings.
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## Peer Discovery on AWS (EC2) {#peer-discovery-aws}
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‎docs/configure.md

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@@ -2174,18 +2174,28 @@ More variables are covered in the [File and Directory Locations guide](./relocat
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<td>
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Standard parameters for the `erl` command used when
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invoking the RabbitMQ Server. This should be overridden for
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debugging purposes only. Overriding this variable
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*replaces* the default value.
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debugging purposes only.
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:::danger
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Setting this variable will replace the defaults provided by RabbitMQ.
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:::
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:::tip
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Consider using `RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS` to add or override individual settings instead.
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:::
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<p>
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<strong>Default</strong>:
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<ul>
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<li>
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**Unix*:**
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`+P 1048576 +t 5000000 +stbt db +zdbbl 128000`
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**UNIX**: `+P 1048576 +t 5000000 +stbt db +zdbbl 128000`
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</li>
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<li>**Windows:** None</li>
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<li>**Windows**: (none)</li>
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</ul>
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</p>
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</td>
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<strong>Default</strong>:
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<ul>
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<li>**Unix*:** None</li>
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<li>**Windows:** None</li>
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<li>**Unix**: (none)</li>
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<li>**Windows**: (none)</li>
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</ul>
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</p>
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</td>

‎docs/networking.md

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@@ -18,6 +18,9 @@ See the License for the specific language governing permissions and
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limitations under the License.
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-->
2020

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import Tabs from '@theme/Tabs';
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import TabItem from '@theme/TabItem';
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# Networking and RabbitMQ
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## Overview {#overview}
@@ -53,6 +56,7 @@ There are several areas which can be configured or tuned. Each has a section in
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* Kernel TCP settings and limits (e.g. [TCP keepalives](#tcp-keepalives) and [open file handle limit](#open-file-handle-limit))
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* How to allow Erlang runtime to accept inbound connections
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when [MacOS Application Firewall](#firewalls-mac-os) is enabled
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* More [advanced settings](#advanced-settings) related to networking
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This guide also covers a few topics closely related to networking:
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@@ -948,10 +952,41 @@ net.ipv4.tcp_keepalive_probes=4
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net.ipv4.tcp_tw_reuse = 1
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```
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## More Advanced Networking Settings {#advanced-settings}
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### The inetrc File
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The [Erlang runtime](./runtime/) allows for a number of hostname resolution-related settings to be tuned
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using a file known as the [inetrc file](http://erlang.org/doc/apps/erts/inet_cfg.html).
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962+
The path to the file can be specified by adding an extra runtime argument using the [`RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS` environment variable](./configure/):
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<Tabs groupId="shell-specific">
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<TabItem value="bash" label="bash" default>
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```bash
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export RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS="-kernel inetrc '/path/to/inetrc.file'"
968+
```
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</TabItem>
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<TabItem value="PowerShell" label="PowerShell">
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```PowerShell
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$env:ERL_INETRC = "-kernel inetrc 'c:\path\to\inetrc.file'"
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```
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</TabItem>
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</Tabs>
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The file can be used to configure a number of settings related to hostname resolution on the node (not system-wide):
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* Hostnames and host addresses (similarly to the [local host file](https://en.wikipedia.org/wiki/Hosts_(file)))
980+
* Local domain name
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* Nameservers
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* Preferred hostname lookup method (e.g. local host file vs. DNS)
983+
* Hostname caching interval
984+
* Search domains
985+
986+
Please consult the [inetrc file documentation](http://erlang.org/doc/apps/erts/inet_cfg.html) to learn more.
951987

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## OS Level Tuning {#os-tuning}
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<a id="os-tuning-intro"></a>
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### OS Level Tuning {#os-tuning}
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Operating system settings can affect operation of RabbitMQ.
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Some are directly related to networking (e.g. TCP settings), others
@@ -961,7 +996,7 @@ Understanding these limits is important, as they may change depending on
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the workload.
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<a id="os-tuning-important-options"></a>
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### Key Relevant Kernel Options
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A few important configurable kernel options include (note that despite option names they
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are effective for both IPv4 and IPv6 connections):
@@ -1053,7 +1088,7 @@ Note that default values for these vary between Linux kernel releases and distri
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Using a recent kernel version (such as 6.x or later) is recommended.
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<a id="os-tuning-important-how-to-configure"></a>
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### sysctl-based Configuration
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Kernel parameter tuning differs from OS to OS. This guide focuses on Linux.
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To configure a kernel parameter interactively, use `sysctl -w` (requires superuser
@@ -1068,7 +1103,7 @@ To make the changes permanent (stick between reboots), they need to be added to
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and [sysctl.conf(5)](http://man7.org/linux/man-pages/man5/sysctl.conf.5.html)
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for more details.
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<a id="os-tuning-outro"></a>
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###
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TCP stack tuning is a broad topic that is covered in much detail elsewhere:
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‎versioned_docs/version-3.13/cluster-formation.md

+4
Original file line numberDiff line numberDiff line change
@@ -307,6 +307,10 @@ Podman is one known example of a tool that can perform such host file modificati
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In order to avoid this, set its [`host_containers_internal_ip` setting](https://github.com/containers/common/blob/main/docs/containers.conf.5.md)
308308
must be set to a blank string.
309309

310+
In environments where container-level settings cannot be tuned, the runtime
311+
can be [configured to ignore the standard local hosts file](./networking#the-inetrc-file)
312+
and only use DNS or a pre-configured set of hostname-to-IP address mappings.
313+
310314

311315
## Peer Discovery on AWS (EC2) {#peer-discovery-aws}
312316

‎versioned_docs/version-3.13/configure.md

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@@ -2162,18 +2162,28 @@ More variables are covered in the [File and Directory Locations guide](./relocat
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<td>
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Standard parameters for the `erl` command used when
21642164
invoking the RabbitMQ Server. This should be overridden for
2165-
debugging purposes only. Overriding this variable
2166-
*replaces* the default value.
2165+
debugging purposes only.
2166+
2167+
:::danger
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2169+
Setting this variable will replace the defaults provided by RabbitMQ.
2170+
2171+
:::
2172+
2173+
:::tip
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2175+
Consider using `RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS` to add or override individual settings instead.
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2177+
:::
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<p>
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<strong>Default</strong>:
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21712182
<ul>
21722183
<li>
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**Unix*:**
2174-
`+P 1048576 +t 5000000 +stbt db +zdbbl 128000`
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**UNIX**: `+P 1048576 +t 5000000 +stbt db +zdbbl 128000`
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</li>
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<li>**Windows:** None</li>
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<li>**Windows**: (none)</li>
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</ul>
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</p>
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</td>
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<strong>Default</strong>:
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<ul>
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<li>**Unix*:** None</li>
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<li>**Windows:** None</li>
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<li>**Unix**: (none) </li>
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<li>**Windows**: (none)</li>
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</ul>
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</p>
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</td>

‎versioned_docs/version-3.13/networking.md

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Original file line numberDiff line numberDiff line change
@@ -18,6 +18,9 @@ See the License for the specific language governing permissions and
1818
limitations under the License.
1919
-->
2020

21+
import Tabs from '@theme/Tabs';
22+
import TabItem from '@theme/TabItem';
23+
2124
# Networking and RabbitMQ
2225

2326
## Overview {#overview}
@@ -53,6 +56,7 @@ There are several areas which can be configured or tuned. Each has a section in
5356
* Kernel TCP settings and limits (e.g. [TCP keepalives](#tcp-keepalives) and [open file handle limit](#open-file-handle-limit))
5457
* How to allow Erlang runtime to accept inbound connections
5558
when [MacOS Application Firewall](#firewalls-mac-os) is enabled
59+
* More [advanced settings](#advanced-settings) related to networking
5660

5761
This guide also covers a few topics closely related to networking:
5862

@@ -948,10 +952,41 @@ net.ipv4.tcp_keepalive_probes=4
948952
net.ipv4.tcp_tw_reuse = 1
949953
```
950954

955+
## More Advanced Networking Settings {#advanced-settings}
956+
957+
### The inetrc File
958+
959+
The [Erlang runtime](./runtime/) allows for a number of hostname resolution-related settings to be tuned
960+
using a file known as the [inetrc file](http://erlang.org/doc/apps/erts/inet_cfg.html).
961+
962+
The path to the file can be specified by adding an extra runtime argument using the [`RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS` environment variable](./configure/):
963+
964+
<Tabs groupId="shell-specific">
965+
<TabItem value="bash" label="bash" default>
966+
```bash
967+
export RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS="-kernel inetrc '/path/to/inetrc.file'"
968+
```
969+
</TabItem>
970+
<TabItem value="PowerShell" label="PowerShell">
971+
```PowerShell
972+
$env:ERL_INETRC = "-kernel inetrc 'c:\path\to\inetrc.file'"
973+
```
974+
</TabItem>
975+
</Tabs>
976+
977+
The file can be used to configure a number of settings related to hostname resolution on the node (not system-wide):
978+
979+
* Hostnames and host addresses (similarly to the [local host file](https://en.wikipedia.org/wiki/Hosts_(file)))
980+
* Local domain name
981+
* Nameservers
982+
* Preferred hostname lookup method (e.g. local host file vs. DNS)
983+
* Hostname caching interval
984+
* Search domains
985+
986+
Please consult the [inetrc file documentation](http://erlang.org/doc/apps/erts/inet_cfg.html) to learn more.
951987

952-
## OS Level Tuning {#os-tuning}
953988

954-
<a id="os-tuning-intro"></a>
989+
### OS Level Tuning {#os-tuning}
955990

956991
Operating system settings can affect operation of RabbitMQ.
957992
Some are directly related to networking (e.g. TCP settings), others
@@ -961,7 +996,7 @@ Understanding these limits is important, as they may change depending on
961996
the workload.
962997

963998

964-
<a id="os-tuning-important-options"></a>
999+
### Key Relevant Kernel Options
9651000

9661001
A few important configurable kernel options include (note that despite option names they
9671002
are effective for both IPv4 and IPv6 connections):
@@ -1053,7 +1088,7 @@ Note that default values for these vary between Linux kernel releases and distri
10531088
Using a recent kernel version (such as 6.x or later) is recommended.
10541089

10551090

1056-
<a id="os-tuning-important-how-to-configure"></a>
1091+
### sysctl-based Configuration
10571092

10581093
Kernel parameter tuning differs from OS to OS. This guide focuses on Linux.
10591094
To configure a kernel parameter interactively, use `sysctl -w` (requires superuser
@@ -1068,7 +1103,7 @@ To make the changes permanent (stick between reboots), they need to be added to
10681103
and [sysctl.conf(5)](http://man7.org/linux/man-pages/man5/sysctl.conf.5.html)
10691104
for more details.
10701105

1071-
<a id="os-tuning-outro"></a>
1106+
###
10721107

10731108
TCP stack tuning is a broad topic that is covered in much detail elsewhere:
10741109

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