These are the two columns in question:

=> (super_column=13957152-234b-11e2-92bc-e0db550199f4,
     (column=attributes, value=, timestamp=1351681613263657)
     (column=blocks, value=A4edo5MhHvojv3Ihx_JkFMsF3ypthtBvAZkoRHsjulw06pez86OHch3K3OpmISnDjHODPoCf69bKcuAZSJj-4Q, timestamp=1351681613263657)
     (column=hash, value=8_p2QaeRaX_QwJbUWQ07ZqlNHei7ixu0MHxgu9oennfYOGfyH6EsEe_LYO8V8EC_1NPL44Gx8B7UhYV9VSb7Lg, timestamp=1351681613263657)
     (column=icon, value=image_jpg, timestamp=1351681613263657)
     (column=is_deleted, value=true, timestamp=1351681613263657)
     (column=is_dir, value=false, timestamp=1351681613263657)
     (column=mime_type, value=image/jpeg, timestamp=1351681613263657)
     (column=mtime, value=1351646803, timestamp=1351681613263657)
     (column=name, value=/Mobile Photos/Photo 2012-10-28 17_13_50.jpeg, timestamp=1351681613263657)
     (column=revision, value=13957152-234b-11e2-92bc-e0db550199f4, timestamp=1351681613263657)
     (column=size, value=1379001, timestamp=1351681613263657)
     (column=thumb_exists, value=true, timestamp=1351681613263657))
=> (super_column=40b7ae4e-2449-11e2-8610-e0db550199f4,
     (column=attributes, value={"posix": 420}, timestamp=1351790781154800)
     (column=blocks, value=9UCDkHNb8-8LuKr2bv9PjKcWCT0v7FCZa0ebNSflES4-o7QD6eYschVaweCKSbR29Dq2IeGl_Cu7BVnYJYphTQ, timestamp=1351790781154800)
     (column=hash, value=kao2EV8jw_wN4EBoMkCXZWCwg3qQ0X6m9_X9JIGkEkiGKJE_JeKgkdoTAkAefXgGtyhChuhWPlWMxl_tX7VZUw, timestamp=1351790781154800)
     (column=icon, value=text_txt, timestamp=1351790781154800)
     (column=is_dir, value=false, timestamp=1351790781154800)
     (column=mime_type, value=text/plain, timestamp=1351790781154800)
     (column=mtime, value=1351378576, timestamp=1351790781154800)
     (column=name, value=/Documents/VIMDocument.txt, timestamp=1351790781154800)
     (column=revision, value=40b7ae4e-2449-11e2-8610-e0db550199f4, timestamp=1351790781154800)
     (column=size, value=13, timestamp=1351790781154800)
     (column=thumb_exists, value=false, timestamp=1351790781154800))


I don't think their size is an issue here.

André

On Nov 8, 2012, at 6:04 PM, Andrey Ilinykh <ailinykh@gmail.com> wrote:

What is the size of columns? Probably those two are huge.


On Thu, Nov 8, 2012 at 4:01 AM, André Cruz <andre.cruz@co.sapo.pt> wrote:
On Nov 7, 2012, at 12:15 PM, André Cruz <andre.cruz@co.sapo.pt> wrote:

> This error also happens on my application that uses pycassa, so I don't think this is the same bug.

I have narrowed it down to a slice between two consecutive columns. Observe this behaviour using pycassa:

>>> DISCO_CASS.col_fam_nsrev.get(uuid.UUID('3cd88d97-ffde-44ca-8ae9-5336caaebc4e'), column_count=2, column_start=uuid.UUID('13957152-234b-11e2-92bc-e0db550199f4')).keys()
DEBUG 2012-11-08 11:55:51,170 pycassa_library.pool:30 6849 139928791262976 Connection 52905488 (xxx:9160) was checked out from pool 51715344
DEBUG 2012-11-08 11:55:53,415 pycassa_library.pool:37 6849 139928791262976 Connection 52905488 (xxx:9160) was checked in to pool 51715344
[UUID('13957152-234b-11e2-92bc-e0db550199f4'), UUID('40b7ae4e-2449-11e2-8610-e0db550199f4')]

A two column slice took more than 2s to return. If I request the next 2 column slice:

>>> DISCO_CASS.col_fam_nsrev.get(uuid.UUID('3cd88d97-ffde-44ca-8ae9-5336caaebc4e'), column_count=2, column_start=uuid.UUID('40b7ae4e-2449-11e2-8610-e0db550199f4')).keys()
DEBUG 2012-11-08 11:57:32,750 pycassa_library.pool:30 6849 139928791262976 Connection 52904912 (xxx:9160) was checked out from pool 51715344
DEBUG 2012-11-08 11:57:32,774 pycassa_library.pool:37 6849 139928791262976 Connection 52904912 (xxx:9160) was checked in to pool 51715344
[UUID('40b7ae4e-2449-11e2-8610-e0db550199f4'), UUID('a364b028-2449-11e2-8882-e0db550199f4')]

This takes 20msec... Is there a rational explanation for this different behaviour? Is there some threshold that I'm running into? Is there any way to obtain more debugging information about this problem?

Thanks,
André