DeployDynamicMirrors
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| This should provide an overview of the issue/functionality/change proposed here. Focus here on what will actually be DONE, summarising that so that other people don't have to read the whole spec. | To spread the mirror load more evenly a new method in apt was developed. This spec describes what must be done to deploy this new method as default. |
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| This section should include a paragraph describing the end-user impact of this change. It is meant to be included in the release notes of the first release in which it is implemented. (Not all of these will actually be included in the release notes, at the release manager's discretion; but writing them is a useful exercise.) It is mandatory. |
TBD |
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| This should cover the _why_: why is this change being proposed, what justifies it, where we see this justified. == Use Cases == == Assumptions == |
The mirror configuration is currently pretty static. It can either be dns based or static in the users sources.list. A more dynamic approach is needed to be able to deal with mirror changes quicker and to distribute the mirror load better. |
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| You can have subsections that better describe specific parts of the issue. | The new apt mirror method works by asking a server for a set of fast closeby mirrors. The current location for this is on launchpad is http://launchpad.net/ubuntu/+countrymirrors-archive |
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| == Implementation == | Apt uses one of those mirrors then for fetching files. It will only update the mirror information if apt-get update is called and it additinally caches them to avoid hitting the central server too hard. |
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| This section should describe a plan of action (the "how") to implement the changes discussed. Could include subsections like: | To enable the new apt mirror methods as default we need to take the following steps: 1. change apt-setup to write mirror:// urls instead of http:// urls it does no longer need to write any mirror info itself 1. change the apt mirror methods to only update the mirror information only if apt sends send IndexFile=True to the methods (to ensure that Packages information is always in sync with the mirror that is downloaded from) [done] 1. Ensure that the cached mirror information is used if the main mirror is not reachable (this should be the case but needs to be tested). |
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| === UI Changes === Should cover changes required to the UI, or specific UI that is required to implement this === Code Changes === Code changes should include an overview of what needs to change, and in some cases even the specific details. === Migration === Include: * data migration, if any * redirects from old URLs to new ones, if any * how users will be pointed to the new way of doing things, if necessary. |
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| It's important that we are able to test new features, and demonstrate them to users. Use this section to describe a short plan that anybody can follow that demonstrates the feature is working. This can then be used during CD testing, and to show off after release. | TBD |
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| This need not be added or completed until the specification is nearing beta. | == Outstanding issues == |
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| == Outstanding Issues == | Launchpad needs to be optimized so that the load from the users asking for mirorr information can be handled. Salgado was confident that this is possible with server side caching. |
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| This should highlight any issues that should be addressed in further specifications, and not problems with the specification itself; since any specification with problems cannot be approved. == BoF agenda and discussion == Use this section to take notes during the BoF; if you keep it in the approved spec, use it for summarising what was discussed and note any options that were rejected. |
Please check the status of this specification in Launchpad before editing it. If it is Approved, contact the Assignee or another knowledgeable person before making changes.
Launchpad Entry: deploy-dynamic-mirrors
Packages affected: apt, launchpad
Summary
To spread the mirror load more evenly a new method in apt was developed. This spec describes what must be done to deploy this new method as default.
Release Note
TBD
Rationale
The mirror configuration is currently pretty static. It can either be dns based or static in the users sources.list. A more dynamic approach is needed to be able to deal with mirror changes quicker and to distribute the mirror load better.
Design
The new apt mirror method works by asking a server for a set of fast closeby mirrors. The current location for this is on launchpad is http://launchpad.net/ubuntu/+countrymirrors-archive
Apt uses one of those mirrors then for fetching files. It will only update the mirror information if apt-get update is called and it additinally caches them to avoid hitting the central server too hard.
To enable the new apt mirror methods as default we need to take the following steps:
change apt-setup to write mirror:// urls instead of http:// urls it does no longer need to write any mirror info itself
change the apt mirror methods to only update the mirror information only if apt sends send IndexFile=True to the methods (to ensure that Packages information is always in sync with the mirror that is downloaded from) [done]
- Ensure that the cached mirror information is used if the main mirror is not reachable (this should be the case but needs to be tested).
Test/Demo Plan
TBD
Outstanding issues
Launchpad needs to be optimized so that the load from the users asking for mirorr information can be handled. Salgado was confident that this is possible with server side caching.
DeployDynamicMirrors (last edited 2008-08-06 16:36:15 by localhost)