Read Timeout in in ovirt_imageio.client.extents()

[abbbi]

hi,

there might be situation where reading the extens from the client takes longer than 60 Seconds:

https://github.com/oVirt/ovirt-imageio/blob/master/ovirt_imageio/_internal/backends/http.py#L53

This leads to the client receiving the extents to run into following exception:

Error:    Unhandled exception occurred [The read operation timed out]
Traceback (most recent call last):
  File "xx", line 432, in main
  File "xx", line 2350, in sbc_pre
  File "xx", line 2211, in imageio_backup
  File "site-packages/ovirt_imageio/client/_api.py", line 289, in extents                                                                                        
  File "site-packages/ovirt_imageio/_internal/backends/http.py", line 306, in extents
  File "site-packages/ovirt_imageio/_internal/backends/http.py", line 502, in _get_extents
  File "lib/python3.11/http/client.py", line 1378, in getresponse
  File "lib/python3.11/http/client.py", line 318, in begin
  File "lib/python3.11/http/client.py", line 279, in _read_status
  File "/lib/python3.11/socket.py", line 706, in readinto
  File "lib/python3.11/ssl.py", line 1278, in recv_into
  File "lib/python3.11/ssl.py", line 1134, in read
TimeoutError: The read operation timed out 

is there any way for the client to change this timeout?

[nirs]

Hey @abbbi,

The traceback does not match upstream code:

ovirt-imageio/ovirt_imageio/client/_api.py

Line 289 in fde3ef0

yield extent

This code is using the nbd backend on local file, but the traceback shows that we use the http backend, so this probably come from:

ovirt-imageio/ovirt_imageio/client/_api.py

Line 341 in fde3ef0

def extents(self, context="zero"):

We use 60 seconds timeut for the http backend. You can modify client.ImageClient to accept a read timeout and use it when opening the http backend.

But the real fix is to support extents with a content range here:

ovirt-imageio/ovirt_imageio/_internal/backends/http.py

Line 508 in fde3ef0

def _get_extents(self, context):

So the client does not need to get extents for the entire image at once. It can request extents for the next 4g range, and yield the result to the caller. When reaching the end it can fetch the next extents from the server.

[abbbi]

hi!

Hey @abbbi,

The traceback does not match upstream code:

yes, the application was using an older version of the SDK.

But the real fix is to support extents with a content range here:

ovirt-imageio/ovirt_imageio/_internal/backends/http.py

Line 508 in fde3ef0

def _get_extents(self, context):
So the client does not need to get extents for the entire image at once. It can request extents for the next 4g range, and yield the result to the caller. When reaching the end it can fetch the next extents from the server.

yes, that explains why the timeout happens with big disks more likely :-)