Not only does it do heavy queries, but it rebuilds the entire metadata set for every single request that is made to the metadata server.  Horribly inefficient! I want to break the metadata code out into its own binary as well.  I will be filing a blueprint to that affect soon.  We definitely need some efficiency cleanup for the metadata server as well.


On Sep 15, 2011, at 11:26 AM, Scott Moser wrote:

> Public bug reported:
> 
> $ time python -c 'import boto.utils; boto.utils.get_instance_metadata()'
> 
> real    0m5.740s
> user    0m0.190s
> sys     0m0.110s
> 
> I've not done a lot of digging on this, but I suspect that 
> nova/api/ec2/cloud.py:get_metadata is doing some heavy queries.
> 
> cloud-init does at least 2 separate hits of the metadata service on
> boot, this means we see something like this in cloud-init.log:
> 
> 2011-09-15 18:17:53,844 - cloud-init[INFO]: cloud-init start running: Thu, 15 Sep 2011 18:17:53 +0000. up 6.01 seconds 
> 2011-09-15 18:17:53,855 - __init__.py[DEBUG]: searching for data source in ['DataSourceNoCloudNet', 'DataSourceOVFNet', 'DataSourceEc2'] 
> 2011-09-15 18:17:53,989 - DataSourceEc2.py[DEBUG]: removed the following from metadata urls: ['http://instance-data:8773'] 
> 2011-09-15 18:17:53,989 - DataSourceEc2.py[DEBUG]: Searching the following metadata urls: ['http://169.254.169.254'] 
> 2011-09-15 18:17:54,350 - DataSourceEc2.py[DEBUG]: Using metadata source: 'http://169.254.169.254' 
> 2011-09-15 18:18:00,027 - __init__.py[DEBUG]: found data source DataSourceEc2 
> 2011-09-15 18:18:00,050 - cloud-init[DEBUG]: found data source: DataSourceEc2 
> 
> 
> Note the 5 second time lapse between 'Using' and 'found'.  Using just indicated there the port was open.  found actually used data from it.
> 
> ** Affects: nova
>     Importance: Undecided
>         Status: New
> 
> -- 
> You received this bug notification because you are a member of Nova Bug
> Team, which is subscribed to OpenStack Compute (nova).
> https://bugs.launchpad.net/bugs/851159
> 
> Title:
>  ec2 metadata service is very slow
> 
> Status in OpenStack Compute (Nova):
>  New
> 
> Bug description:
>  $ time python -c 'import boto.utils;
>  boto.utils.get_instance_metadata()'
> 
>  real    0m5.740s
>  user    0m0.190s
>  sys     0m0.110s
> 
>  I've not done a lot of digging on this, but I suspect that 
>  nova/api/ec2/cloud.py:get_metadata is doing some heavy queries.
> 
>  cloud-init does at least 2 separate hits of the metadata service on
>  boot, this means we see something like this in cloud-init.log:
> 
>  2011-09-15 18:17:53,844 - cloud-init[INFO]: cloud-init start running: Thu, 15 Sep 2011 18:17:53 +0000. up 6.01 seconds 
>  2011-09-15 18:17:53,855 - __init__.py[DEBUG]: searching for data source in ['DataSourceNoCloudNet', 'DataSourceOVFNet', 'DataSourceEc2'] 
>  2011-09-15 18:17:53,989 - DataSourceEc2.py[DEBUG]: removed the following from metadata urls: ['http://instance-data:8773'] 
>  2011-09-15 18:17:53,989 - DataSourceEc2.py[DEBUG]: Searching the following metadata urls: ['http://169.254.169.254'] 
>  2011-09-15 18:17:54,350 - DataSourceEc2.py[DEBUG]: Using metadata source: 'http://169.254.169.254' 
>  2011-09-15 18:18:00,027 - __init__.py[DEBUG]: found data source DataSourceEc2 
>  2011-09-15 18:18:00,050 - cloud-init[DEBUG]: found data source: DataSourceEc2 
> 
> 
>  Note the 5 second time lapse between 'Using' and 'found'.  Using just indicated there the port was open.  found actually used data from it.
> 
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