| Message ID | 20200529151952.15184-1-idryomov@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | libceph: support for replica reads | expand |
On Fri, May 29, 2020 at 6:57 PM Jason Dillaman <jdillama@redhat.com> wrote: > > lgtm -- couple questions: > > 1) the client adding the options will be responsible for determining if it's safe to enable read-from-replica/balanced reads (i.e. OSDs >= octopus)? Yes, we can't easily check require_osd_release or similar in the kernel. This is opt-in, and I'll add a warning together with the description of the new options to the man page. > 2) is there a way to determine if the kernel supports the new options (or will older kernels just ignore the options w/o complaining)? i.e. can ceph-csi safely add the argument regardless? No, older kernels will error out. I think ceph-csi would handle this the same way ceph quotas are handled (i.e. with the list of known "good" kernel versions) or alternatively just attempt to map with and then without crush_location and read_balance=localize (probably less appealing given that the kernel version list infrastructure is already in place). Thanks, Ilya
On Fri, May 29, 2020 at 7:21 PM Ilya Dryomov <idryomov@gmail.com> wrote: > > On Fri, May 29, 2020 at 6:57 PM Jason Dillaman <jdillama@redhat.com> wrote: > > > > lgtm -- couple questions: > > > > 1) the client adding the options will be responsible for determining if it's safe to enable read-from-replica/balanced reads (i.e. OSDs >= octopus)? > > Yes, we can't easily check require_osd_release or similar in the > kernel. This is opt-in, and I'll add a warning together with the > description of the new options to the man page. > > > 2) is there a way to determine if the kernel supports the new options (or will older kernels just ignore the options w/o complaining)? i.e. can ceph-csi safely add the argument regardless? > > No, older kernels will error out. I think ceph-csi would handle > this the same way ceph quotas are handled (i.e. with the list of > known "good" kernel versions) or alternatively just attempt to map > with and then without crush_location and read_balance=localize ^^^ Typo, read_policy=localize. Thanks, Ilya
Hello, This adds support for replica reads (balanced and localized reads) to rbd and ceph. crush_location syntax is slightly different, see patch 3 for details. Thanks, Ilya Ilya Dryomov (5): libceph: add non-asserting rbtree insertion helper libceph: decode CRUSH device/bucket types and names libceph: crush_location infrastructure libceph: support for balanced and localized reads libceph: read_policy option include/linux/ceph/libceph.h | 13 +- include/linux/ceph/osd_client.h | 1 + include/linux/ceph/osdmap.h | 19 +- include/linux/crush/crush.h | 6 + net/ceph/ceph_common.c | 51 +++++ net/ceph/crush/crush.c | 3 + net/ceph/debugfs.c | 6 +- net/ceph/osd_client.c | 92 +++++++- net/ceph/osdmap.c | 361 +++++++++++++++++++++++++++----- 9 files changed, 491 insertions(+), 61 deletions(-)