Daymet OPENDAP

[rmcd]

I am accessing Daymet through the OPENDAP endpoint https://thredds.daac.ornl.gov/thredds/dodsC/daymet-v4-agg/na.ncml. I'm experiencing very slow download speeds. On the USGS VPN I'm getting ~2Kb/s and from home without VPN I'm getting ~5Mb/s. In my experience this is quite slow. I am interpolating daymet variables to Alaska's HUC12, and generally I have I request the data by year and by quarter to stay within the allowable size of the request. This has been fine in the past but now in addition to the slow download speeds and maybe because of it I'm also getting curl timeout errors. I changed the download request to monthly chunks and that is better but eventually I run into the same timeout errors. Just checking and asking to see if there is something on the server side that might be slowing the downloads down? For more context I'm using python and xarray to open and process the data via xarray using the OPENDAP endpoint linked above. Any help would be appreciated.

[ORNLx - mthornton]

Hi rmcd,
Just wanted to share that this same question was address at the same time frame in another post with the same title `Daymet OPENDAP`.
Thanks,
Michele

[miketaku111]

rmcd wrote:
> I am accessing Daymet through the OPENDAP endpoint
> https://thredds.daac.ornl.gov/thredds/dodsC/daymet-v4-agg/na.ncml. I'm
> experiencing very slow download speeds. On the USGS VPN I'm getting ~2Kb/s
> and from home without VPN I'm getting ~5Mb/s. In my experience this is
> quite slow. I am interpolating daymet variables to Alaska's HUC12, and
> generally I have I request the data by year and by quarter to stay within
> the allowable size of the request. This has been fine in the past but now
> in addition to the slow download speeds and maybe because of it I'm also
> getting curl timeout errors. I changed the download request to monthly
> chunks and that is better but eventually I run into the same timeout
> errors. Just checking and asking to see if there is something on the
> server side that might be slowing the downloads down? For more context I'm
> using python and xarray to open and process the data via xarray using the
> OPENDAP endpoint linked above. Any help would be appreciated.

Hi there! just saw this thread and want to ask you does there was a server-side issue causing slow download speeds and curl timeout errors when accessing Daymet data through the OPENDAP endpoint, and how can this be improved?

[ORNL - yaxingwei]

Hi @miketaku111 ,

Thanks for contacting us!

We don't believe the extra download speed on USGS VPN was due to an issue with our servers. But our servers did have some heavy loads, which could cause occasional timeout errors. We are conducting a systematic analysis to find out how the performance of the servers were affected and find out ways to improve their performance and availability. We will keep you updated.

While at the same time, if you can share any information, like how often you got the errors, number of your concurrent requests, and data size of your typical requests, it will be very helpful for us to diagnose the issues. Thanks!