qemu: Don't log partial buffer reads from qemu monitor

[libvirt] [PATCH 0/2] qemu: Don't log partial buffer reads from qemu monitor

Peter Krempa posted 2 patches 6 years, 3 months ago

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Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/libvirt tags/patchew/cover.1513854816.git.pkrempa@redhat.com

src/qemu/qemu_monitor.c      | 4 ++--
src/qemu/qemu_monitor_json.c | 3 +++
src/util/virprobe.h          | 8 ++++++++
3 files changed, 13 insertions(+), 2 deletions(-)

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[libvirt] [PATCH 0/2] qemu: Don't log partial buffer reads from qemu monitor

Posted by Peter Krempa 6 years, 3 months ago

I was debugging a case where 200 snapshots of a disk would result in a
VERY long reconnect time after libvirtd restart when debug logging was
enabled.

I've figured out that qemu responds with 9MiB of json after calling
"query-named-block-nodes" and this resulted in > 26 GiB of libvirtd
debug log just to process the message.

I'll report the qemu flaw separately.

Peter Krempa (2):
  util: probe: Add quiet versions of the "PROBE" macro
  qemu: monitor: Decrease logging verbosity

 src/qemu/qemu_monitor.c      | 4 ++--
 src/qemu/qemu_monitor_json.c | 3 +++
 src/util/virprobe.h          | 8 ++++++++
 3 files changed, 13 insertions(+), 2 deletions(-)

-- 
2.15.0

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Re: [libvirt] [PATCH 0/2] qemu: Don't log partial buffer reads from qemu monitor

Posted by Ján Tomko 6 years, 3 months ago

On Thu, Dec 21, 2017 at 12:16:50PM +0100, Peter Krempa wrote:
>I was debugging a case where 200 snapshots of a disk would result in a
>VERY long reconnect time after libvirtd restart when debug logging was
>enabled.
>
>I've figured out that qemu responds with 9MiB of json after calling
>"query-named-block-nodes" and this resulted in > 26 GiB of libvirtd
>debug log just to process the message.
>
>I'll report the qemu flaw separately.
>
>Peter Krempa (2):
>  util: probe: Add quiet versions of the "PROBE" macro
>  qemu: monitor: Decrease logging verbosity
>
> src/qemu/qemu_monitor.c      | 4 ++--
> src/qemu/qemu_monitor_json.c | 3 +++
> src/util/virprobe.h          | 8 ++++++++
> 3 files changed, 13 insertions(+), 2 deletions(-)
>

ACK series with the typos fixed.

Jan
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