OpenTelemetry should use an allowed port

[bboreham]

What are you trying to achieve?

Conformance with Internet standards.

What did you expect to see?

A port number in the range of User Ports, and ideally one assigned by IANA.

Additional context.

OpenTelemetry is using port 55680. According to RFC 6335,

a port number in [the Dynamic Ports range (49152-65535)] MUST NOT be used as a service identifier.

On a practical front, ports in the high range are usually allocated dynamically by the operating system, so there is some random chance 55680 is in use for that purpose and your OpenTelemetry receiver will not start.

[andrewhsu]

from the spec issue triage mtg today, setting to P1 so we can have a quick decision. perhaps setting the port number a required parameter will allow us to set it to a default we want to choose later.

[mtwo]

Following up from the same meeting. I'm making an IANA application now. I'll include the governance committee and @tigrannajaryan in all communications with them.

[mtwo]

@tigrannajaryan @bogdandrutu three questions that I need answered before I file this:

• Do we have a list of defined TXT keys? I've entered our service name as 'otlp'
• "Please describe how your protocol supports security" - what should I enter for this
• I'm assuming that we only use TCP and don't use UDP - is this accurate?

[Oberon00]

Please describe how your protocol supports security

I would assume it is enough to mention that the protocol is HTTPS based (it is, right?)

[mtwo]

@Oberon00 I added this: "OTLP uses client transfer security by default. While users can opt out by enabling the OTEL_EXPORTER_OTLP_METRIC_INSECURE SDK flags, we do not expect this to be common."

@tigrannajaryan let me know what I should enter for the list of TXT keys and I'll submit.

[tigrannajaryan]

Does this proposal mean we need to change the default port? It will break a bunch of software that relies on the defaults.

[mtwo]

It does. Do you think the benefits of having a reserved port outweigh the pre-GA change? Bogdan also proposed an alternative of making the port a required parameter during RC and then defaulting it (via an optional parameter) to the newly-assigned port at GA.

If you think that it's too late and we should stick with our current port, then we can close this and I won't submit the request to the IANA.

[bboreham]

Server-side you can have the code listen to both old and new ports. The only hard break is for new-built clients that cannot be configured to talk to old servers.

[mtwo]

I'll add this as a discussion topic at Wednesday's Collector SIG meeting

[tigrannajaryan]

Let's discuss. Perhaps we can come up with some transitional backwards compatibility plan, e.g. receive on both old and new port during a transition period.

[tigrannajaryan]

Also, we need 2 ports. OTLP/HTTP uses a different port 55681.

[Oberon00]

Why doesn't OTLP/HTTP use the normal HTTP port?

[tigrannajaryan]

@Oberon00 technical limitations of Go-based implementation: open-telemetry/opentelemetry-collector#1223

It may be possible to overcome the limitation and I'd highly prefer to use the same port if possible. We have an open issue open-telemetry/opentelemetry-collector#1256 but no known solution yet.

[tigrannajaryan]

Why doesn't OTLP/HTTP use the normal HTTP port?

@Oberon00 I think I misread your question. What do you mean by normal HTTP port? 80/443? They are privileged port numbers and I don't think we want to impose root permissions as a requirement to use OTLP/HTTP.

[tigrannajaryan]

Discussed this in TC meeting today. We are going to look into 2 issues before making a decision on this:

• Are we able to have a reasonably painless transition for existing OTLP users (old/new port number support on sending/receiving side). I will look into this.
• Are we able to use one port for OTLP/gRPC and OTLP/HTTP. Depending on this we may need to request registration for 1 port or for 2 ports. @bogdandrutu is going to look into this.

[tigrannajaryan]

I had a quick look at the old/new port number support.

• It is not difficult to support receiving on both ports simultaneously in the Collector. We will update the OTLP receiver in the Collector to use a new default. The OTLP receiver will also enable the legacy port receiving when the default configuration is used. This way any users that have the default (omitted) port in the Collector config file will not be affected because of the change of the default port. User that have non-default port in the config likewise won't be affected since the port is explicitly specified. We will keep this dual port receiving for a few months and can retire the legacy port eventually.

• Collector's OTLP exporter currently requires that the destination host and port are explicitly specified. So changing the default port in the OTLP specification has no effect on OTLP exporter in the Collector.

• The SDK exporters have a notion of the default OTLP port, so if we change the default then existing applications/instrumentations will be affected. However, given that vast majority of SDKs are expected to send to the Collector the SDKs will work fine before or after the default port is changed in the SDK provided that the Collector is updated first to the new version which supports receiving on both ports.

• Backends that currently implement may continue using the legacy port number provided that they are receiving from the Collector where that port number is explicitly specified (this should be the majority of use cases). Backends will be however advised to change to the new port or support receiving of both ports like Collector does.

I believe this is sufficient to change the port number without causing pain to current users. Once we have the outcome of the investigation from Bogdan we can move forward.

[tigrannajaryan]

@bboreham @mtwo what does IANA registration process require? Do we choose a port number and then apply for registration or we ask for IANA to choose a port number for us first? If it is the former then I assume we just pick something that shows as "Unassigned" in the IANA list?

[mtwo]

Correct, we can request a specific port or have them auto assign an open one

…

________________________________ From: Tigran Najaryan <notifications@github.com> Sent: Thursday, November 5, 2020 7:12:17 AM To: open-telemetry/opentelemetry-specification <opentelemetry-specification@noreply.github.com> Cc: Morgan McLean <morgan_mclean@hotmail.com>; Mention <mention@noreply.github.com> Subject: Re: [open-telemetry/opentelemetry-specification] OpenTelemetry should use an allowed port (#1148) @bboreham<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fbboreham&data=04%7C01%7C%7C07cb700b18cc4e1418f808d8819d3019%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637401859396032475%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=96opgQJjyoDYJ8LLk7BoFeDd%2BChmaFOm7UiHIKKt45A%3D&reserved=0> @mtwo<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fmtwo&data=04%7C01%7C%7C07cb700b18cc4e1418f808d8819d3019%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637401859396042468%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=k0UG18iRBW8rUa1jaRHUR3uRrivRFSrQRKLAtxqflRE%3D&reserved=0> what does IANA registration process require? Do we choose a port number and then apply for registration or we ask for IANA to choose a port number for us first? If it is the former then I assume we just pick something that shows as "Unassigned" in the IANA list<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.iana.org%2Fassignments%2Fservice-names-port-numbers%2Fservice-names-port-numbers.txt&data=04%7C01%7C%7C07cb700b18cc4e1418f808d8819d3019%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637401859396062460%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=pZX07Bgt2kZnpVvy3x4YIOkTdSoREIT3NesFANbyeqs%3D&reserved=0>? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fopen-telemetry%2Fopentelemetry-specification%2Fissues%2F1148%23issuecomment-722439567&data=04%7C01%7C%7C07cb700b18cc4e1418f808d8819d3019%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637401859396072456%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=VMk0KITDp%2Bj6OOYUW8hkmJtW00DVTOWaFosl%2FE3%2FvBk%3D&reserved=0>, or unsubscribe<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fnotifications%2Funsubscribe-auth%2FAAIXLK6SO2XSGMASMEEL2WTSOK6FDANCNFSM4TCC7DSA&data=04%7C01%7C%7C07cb700b18cc4e1418f808d8819d3019%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637401859396092445%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=fvlldvncyiVhBqBnv7RSoBS%2BKtmYbXIFA6BuSK%2FvJI0%3D&reserved=0>.

[tigrannajaryan]

OK, from what I see 4317-4319 range is unassigned. We can request 4317 and if it turns out OTLP/HTTP needs a separate port then 4318 in addition to that (unless port choices were already made - I don't see anything in this thread).

[mtwo]

No choices have been made, I’ll submit the application for 4317 tomorrow morning. Can you answer my question about TXT records? I need to put that in the submission.

…

________________________________ From: Tigran Najaryan <notifications@github.com> Sent: Thursday, November 5, 2020 10:58:17 AM To: open-telemetry/opentelemetry-specification <opentelemetry-specification@noreply.github.com> Cc: Morgan McLean <morgan_mclean@hotmail.com>; Mention <mention@noreply.github.com> Subject: Re: [open-telemetry/opentelemetry-specification] OpenTelemetry should use an allowed port (#1148) OK, from what I see 4317-4319 range is unassigned. We can request 4317 and if it turns out OTLP/HTTP needs a separate port then 4318 in addition to that (unless port choices were already made - I don't see anything in this thread). — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fopen-telemetry%2Fopentelemetry-specification%2Fissues%2F1148%23issuecomment-722574974&data=04%7C01%7C%7Cf141ad532ab94a8d1a3d08d881bcc220%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637401994989204765%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=cx49vQE5INQilcANHcd8DFbHLdYc4nSqKwcb6hn7Czo%3D&reserved=0>, or unsubscribe<https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fnotifications%2Funsubscribe-auth%2FAAIXLK5MAM63CZNLJNTMDSTSOLYUTANCNFSM4TCC7DSA&data=04%7C01%7C%7Cf141ad532ab94a8d1a3d08d881bcc220%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637401994989214759%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=x%2BnbPxiTpBrcYfAfKUX9EeQlbYlsEw%2BpKG06EZbGDQY%3D&reserved=0>.

[tigrannajaryan]

@mtwo I do not fully understand what the TXT record is for in the context of port registration. Can you clarify or point me to the relevant part in the port registration RFC?

Assuming this is the name of the protocol we may need to wait until we have a decision about using 1 or 2 ports. If it is one port we will call it "otlp", if 2 ports then it will be "otlp/grpc" and "otlp/http".