mirror of
https://github.com/ceph/ceph
synced 2024-12-11 22:18:18 +00:00
166 lines
7.3 KiB
ReStructuredText
166 lines
7.3 KiB
ReStructuredText
=====================================
|
|
Configuring Monitor/OSD Interaction
|
|
=====================================
|
|
|
|
After you have completed your initial Ceph configuration, you may deploy and run
|
|
Ceph. When you execute a command such as ``ceph health`` or ``ceph -s``, the
|
|
monitor reports on the current state of the cluster. The monitor knows about the
|
|
cluster by requiring reports from each OSD, and by receiving reports from OSDs
|
|
about the status of their neighboring OSDs. If the monitor doesn't receive
|
|
reports, or if it receives reports of changes in the cluster, the monitor
|
|
updates the status of the cluster.
|
|
|
|
Ceph provides reasonable default settings for monitor/OSD interaction. However,
|
|
you may override the defaults. The following sections describe how Ceph monitors
|
|
and OSDs interact for the purposes of monitoring.
|
|
|
|
|
|
OSDs Check Heartbeats
|
|
=====================
|
|
|
|
Each OSD checks the heartbeat of other OSDs every 6 seconds. You can change the
|
|
heartbeat interval by adding an ``osd heartbeat interval`` setting under the
|
|
``[osd]`` section of your Ceph configuration file, or by setting the value at
|
|
runtime. If an OSD doesn't show a heartbeat within a 20 second grace period, the
|
|
cluster may consider the OSD ``down``. You may change this grace period by
|
|
adding an ``osd heartbeat grace`` setting under the ``[osd]`` section of your
|
|
Ceph configuration file, or by setting the value at runtime.
|
|
|
|
|
|
.. ditaa:: +---------+ +---------+
|
|
| OSD 1 | | OSD 2 |
|
|
+---------+ +---------+
|
|
| |
|
|
|----+ Heartbeat |
|
|
| | Interval |
|
|
|<---+ Exceeded |
|
|
| |
|
|
| Check |
|
|
| Heartbeat |
|
|
|------------------->|
|
|
| |
|
|
|<-------------------|
|
|
| Heart Beating |
|
|
| |
|
|
|----+ Heartbeat |
|
|
| | Interval |
|
|
|<---+ Exceeded |
|
|
| |
|
|
| Check |
|
|
| Heartbeat |
|
|
|------------------->|
|
|
| |
|
|
|----+ Grace |
|
|
| | Period |
|
|
|<---+ Exceeded |
|
|
| |
|
|
|----+ Mark |
|
|
| | OSD 2 |
|
|
|<---+ Down |
|
|
|
|
|
|
|
|
OSDs Report Down OSDs
|
|
=====================
|
|
|
|
By default, an OSD must report to the monitors that another OSD is ``down``
|
|
three times before the monitors acknowledge that the reported OSD is ``down``.
|
|
You can change the minimum number of ``osd down`` reports by adding an ``osd min
|
|
down reports`` setting under the ``[osd]`` section of your Ceph configuration
|
|
file, or by setting the value at runtime. By default, only one OSD is required
|
|
to report another OSD down. You can change the number of OSDs required to report
|
|
a monitor down by adding an ``osd min down reporters`` setting under the
|
|
``[osd]`` section of your Ceph configuration file, or by setting the value at
|
|
runtime.
|
|
|
|
|
|
.. ditaa:: +---------+ +---------+
|
|
| OSD 1 | | Monitor |
|
|
+---------+ +---------+
|
|
| |
|
|
| OSD 2 Is Down |
|
|
|-------------->|
|
|
| |
|
|
| OSD 2 Is Down |
|
|
|-------------->|
|
|
| |
|
|
| OSD 2 Is Down |
|
|
|-------------->|
|
|
| |
|
|
| |----------+ Mark
|
|
| | | OSD 2
|
|
| |<---------+ Down
|
|
|
|
|
|
OSDs Report Peering Failure
|
|
===========================
|
|
|
|
If an OSD cannot peer with any of the OSDs defined in its Ceph configuration
|
|
file, it will ping the monitor for the most recent copy of the cluster map every
|
|
30 seconds. You can change the monitor heartbeat interval by adding an ``osd mon
|
|
heartbeat interval`` setting under the ``[osd]`` section of your Ceph
|
|
configuration file, or by setting the value at runtime.
|
|
|
|
.. ditaa:: +---------+ +---------+ +-------+ +---------+
|
|
| OSD 1 | | OSD 2 | | OSD 3 | | Monitor |
|
|
+---------+ +---------+ +-------+ +---------+
|
|
| | | |
|
|
| Request To | | |
|
|
| Peer | | |
|
|
|-------------->| | |
|
|
|<--------------| | |
|
|
| Peering | |
|
|
| | |
|
|
| Request To | |
|
|
| Peer | |
|
|
|----------------------------->| |
|
|
| |
|
|
|----+ OSD Monitor |
|
|
| | Heartbeat |
|
|
|<---+ Interval Exceeded |
|
|
| |
|
|
| Failed to Peer with OSD 3 |
|
|
|-------------------------------------------->|
|
|
|<--------------------------------------------|
|
|
| Receive New Cluster Map |
|
|
|
|
|
|
OSDs Report Their Status
|
|
========================
|
|
|
|
If an OSD doesn't report to the monitor once at least every 120 seconds, the
|
|
monitor will consider the OSD ``down``. You can change the monitor report
|
|
interval by adding an ``osd mon report interval max`` setting under the
|
|
``[osd]`` section of your Ceph configuration file, or by setting the value at
|
|
runtime. The OSD attempts to report on its status every 30 seconds. You can
|
|
change the OSD report interval by adding an ``osd mon report interval min``
|
|
setting under the ``[osd]`` section of your Ceph configuration file, or by
|
|
setting the value at runtime.
|
|
|
|
|
|
.. ditaa:: +---------+ +---------+
|
|
| OSD 1 | | Monitor |
|
|
+---------+ +---------+
|
|
| |
|
|
|----+ Report Min |
|
|
| | Interval |
|
|
|<---+ Exceeded |
|
|
| |
|
|
| Report To |
|
|
| Monitor |
|
|
|------------------->|
|
|
| |
|
|
|----+ Report Min |
|
|
| | Interval |
|
|
|<---+ Exceeded |
|
|
| |
|
|
| No Report |
|
|
+----+ Report Max
|
|
| | Interval
|
|
|<---+ Exceeded
|
|
|
|
|
+----+ Mark
|
|
| | OSD 1
|
|
|<---+ Down
|
|
|