ctdb-script.options
5
ctdb
CTDB - clustered TDB database
ctdb-script.options
CTDB scripts configuration files
DESCRIPTION
Location
Each CTDB script has 2 possible locations for its configuration options:
/usr/local/etc/ctdb/script.options
This is a catch-all global file for general purpose
scripts and for options that are used in multiple event
scripts.
SCRIPT.options
That is, options for
SCRIPT are
placed in a file alongside the script, with a ".script"
suffix added. This style is usually recommended for event
scripts.
Options in this script-specific file override those in
the global file.
Contents
These files should include simple shell-style variable
assignments and shell-style comments.
Monitoring Thresholds
Event scripts can monitor resources or services. When a
problem is detected, it may be better to warn about a problem
rather than to immediately fail monitoring and mark a node as
unhealthy. CTDB provides support for event scripts to do
threshold-based monitoring.
A threshold setting looks like
WARNING_THRESHOLD:ERROR_THRESHOLD.
If the number of problems is ≥ WARNING_THRESHOLD then the
script will log a warning and continue. If the number
problems is ≥ ERROR_THRESHOLD then the script will log an
error and exit with failure, causing monitoring to fail. Note
that ERROR_THRESHOLD is optional, and follows the optional
colon (:) separator.
NETWORK CONFIGURATION
10.interface
This event script handles monitoring of interfaces using by
public IP addresses.
CTDB_PARTIALLY_ONLINE_INTERFACES=yes|no
Whether one or more offline interfaces should cause a
monitor event to fail if there are other interfaces that
are up. If this is "yes" and a node has some interfaces
that are down then ctdb status will
display the node as "PARTIALLYONLINE".
Note that CTDB_PARTIALLY_ONLINE_INTERFACES=yes is not
generally compatible with NAT gateway or LVS. NAT
gateway relies on the interface configured by
CTDB_NATGW_PUBLIC_IFACE to be up and LVS replies on
CTDB_LVS_PUBLIC_IFACE to be up. CTDB does not check if
these options are set in an incompatible way so care is
needed to understand the interaction.
Default is "no".
11.natgw
Provides CTDB's NAT gateway functionality.
NAT gateway is used to configure fallback routing for nodes
when they do not host any public IP addresses. For example,
it allows unhealthy nodes to reliably communicate with
external infrastructure. One node in a NAT gateway group will
be designated as the NAT gateway leader node and other (follower)
nodes will be configured with fallback routes via the NAT
gateway leader node. For more information, see the
NAT GATEWAY section in
ctdb
7.
CTDB_NATGW_DEFAULT_GATEWAY=IPADDR
IPADDR is an alternate network gateway to use on the NAT
gateway leader node. If set, a fallback default route
is added via this network gateway.
No default. Setting this variable is optional - if not
set that no route is created on the NAT gateway leader
node.
CTDB_NATGW_NODES=FILENAME
FILENAME contains the list of nodes that belong to the
same NAT gateway group.
File format:
IPADDR follower-only
IPADDR is the private IP address of each node in the NAT
gateway group.
If "follower-only" is specified then the corresponding node
can not be the NAT gateway leader node. In this case
CTDB_NATGW_PUBLIC_IFACE and
CTDB_NATGW_PUBLIC_IP are optional and
unused.
No default, usually
/usr/local/etc/ctdb/natgw_nodes when enabled.
CTDB_NATGW_PRIVATE_NETWORK=IPADDR/MASK
IPADDR/MASK is the private sub-network that is
internally routed via the NAT gateway leader node. This
is usually the private network that is used for node
addresses.
No default.
CTDB_NATGW_PUBLIC_IFACE=IFACE
IFACE is the network interface on which the
CTDB_NATGW_PUBLIC_IP will be configured.
No default.
CTDB_NATGW_PUBLIC_IP=IPADDR/MASK
IPADDR/MASK indicates the IP address that is used for
outgoing traffic (originating from
CTDB_NATGW_PRIVATE_NETWORK) on the NAT gateway leader
node. This must not be a
configured public IP address.
No default.
CTDB_NATGW_STATIC_ROUTES=IPADDR/MASK[@GATEWAY] ...
Each IPADDR/MASK identifies a network or host to which
NATGW should create a fallback route, instead of
creating a single default route. This can be used when
there is already a default route, via an interface that
can not reach required infrastructure, that overrides
the NAT gateway default route.
If GATEWAY is specified then the corresponding route on
the NATGW leader node will be via GATEWAY. Such routes
are created even if
CTDB_NATGW_DEFAULT_GATEWAY is not
specified. If GATEWAY is not specified for some
networks then routes are only created on the NATGW
leader node for those networks if
CTDB_NATGW_DEFAULT_GATEWAY is
specified.
This should be used with care to avoid causing traffic
to unnecessarily double-hop through the NAT gateway
leader, even when a node is hosting public IP addresses.
Each specified network or host should probably have a
corresponding automatically created link route or static
route to avoid this.
No default.
Example
CTDB_NATGW_NODES=/usr/local/etc/ctdb/natgw_nodes
CTDB_NATGW_PRIVATE_NETWORK=192.168.1.0/24
CTDB_NATGW_DEFAULT_GATEWAY=10.0.0.1
CTDB_NATGW_PUBLIC_IP=10.0.0.227/24
CTDB_NATGW_PUBLIC_IFACE=eth0
A variation that ensures that infrastructure (ADS, DNS, ...)
directly attached to the public network (10.0.0.0/24) is
always reachable would look like this:
CTDB_NATGW_NODES=/usr/local/etc/ctdb/natgw_nodes
CTDB_NATGW_PRIVATE_NETWORK=192.168.1.0/24
CTDB_NATGW_PUBLIC_IP=10.0.0.227/24
CTDB_NATGW_PUBLIC_IFACE=eth0
CTDB_NATGW_STATIC_ROUTES=10.0.0.0/24
Note that CTDB_NATGW_DEFAULT_GATEWAY is
not specified.
13.per_ip_routing
Provides CTDB's policy routing functionality.
A node running CTDB may be a component of a complex network
topology. In particular, public addresses may be spread
across several different networks (or VLANs) and it may not be
possible to route packets from these public addresses via the
system's default route. Therefore, CTDB has support for
policy routing via the 13.per_ip_routing
eventscript. This allows routing to be specified for packets
sourced from each public address. The routes are added and
removed as CTDB moves public addresses between nodes.
For more information, see the POLICY
ROUTING section in
ctdb
7.
CTDB_PER_IP_ROUTING_CONF=FILENAME
FILENAME contains elements for constructing the desired
routes for each source address.
The special FILENAME value
__auto_link_local__ indicates that no
configuration file is provided and that CTDB should
generate reasonable link-local routes for each public IP
address.
File format:
IPADDR DEST-IPADDR/MASK GATEWAY-IPADDR
No default, usually
/usr/local/etc/ctdb/policy_routing
when enabled.
CTDB_PER_IP_ROUTING_RULE_PREF=NUM
NUM sets the priority (or preference) for the routing
rules that are added by CTDB.
This should be (strictly) greater than 0 and (strictly)
less than 32766. A priority of 100 is recommended, unless
this conflicts with a priority already in use on the
system. See
ip
8, for more details.
CTDB_PER_IP_ROUTING_TABLE_ID_LOW=LOW-NUM,
CTDB_PER_IP_ROUTING_TABLE_ID_HIGH=HIGH-NUM
CTDB determines a unique routing table number to use for
the routing related to each public address. LOW-NUM and
HIGH-NUM indicate the minimum and maximum routing table
numbers that are used.
ip
8 uses some
reserved routing table numbers below 255. Therefore,
CTDB_PER_IP_ROUTING_TABLE_ID_LOW should be (strictly)
greater than 255.
CTDB uses the standard file
/etc/iproute2/rt_tables to maintain
a mapping between the routing table numbers and labels.
The label for a public address
ADDR will look like
ctdb.addr. This means that
the associated rules and routes are easy to read (and
manipulate).
No default, usually 1000 and 9000.
Example
CTDB_PER_IP_ROUTING_CONF=/usr/local/etc/ctdb/policy_routing
CTDB_PER_IP_ROUTING_RULE_PREF=100
CTDB_PER_IP_ROUTING_TABLE_ID_LOW=1000
CTDB_PER_IP_ROUTING_TABLE_ID_HIGH=9000
91.lvs
Provides CTDB's LVS functionality.
For a general description see the LVS
section in ctdb
7.
CTDB_LVS_NODES=FILENAME
FILENAME contains the list of nodes that belong to the
same LVS group.
File format:
IPADDR follower-only
IPADDR is the private IP address of each node in the LVS
group.
If "follower-only" is specified then the corresponding node
can not be the LVS leader node. In this case
CTDB_LVS_PUBLIC_IFACE and
CTDB_LVS_PUBLIC_IP are optional and
unused.
No default, usually
/usr/local/etc/ctdb/lvs_nodes when enabled.
CTDB_LVS_PUBLIC_IFACE=INTERFACE
INTERFACE is the network interface that clients will use
to connection to CTDB_LVS_PUBLIC_IP.
This is optional for follower-only nodes.
No default.
CTDB_LVS_PUBLIC_IP=IPADDR
CTDB_LVS_PUBLIC_IP is the LVS public address. No
default.
SERVICE CONFIGURATION
CTDB can be configured to manage and/or monitor various NAS (and
other) services via its eventscripts.
In the simplest case CTDB will manage a service. This means the
service will be started and stopped along with CTDB, CTDB will
monitor the service and CTDB will do any required
reconfiguration of the service when public IP addresses are
failed over.
20.multipathd
Provides CTDB's Linux multipathd service management.
It can monitor multipath devices to ensure that active paths
are available.
CTDB_MONITOR_MPDEVICES=MP-DEVICE-LIST
MP-DEVICE-LIST is a list of multipath devices for CTDB to monitor?
No default.
31.clamd
This event script provide CTDB's ClamAV anti-virus service
management.
This eventscript is not enabled by default. Use ctdb
enablescript to enable it.
CTDB_CLAMD_SOCKET=FILENAME
FILENAME is the socket to monitor ClamAV.
No default.
40.vsftpd
Provides CTDB's vsftpd service management.
CTDB_VSFTPD_MONITOR_THRESHOLDS=THRESHOLDS
THRESHOLDS indicates how many consecutive monitoring
attempts need to report that vsftpd is not listening on
TCP port 21 before a warning is logged and before
monitoring fails. See the Monitoring
Thresholds for a description of how
monitoring thresholds work.
Default is 1:2.
48.netbios
Provides CTDB's NetBIOS service management.
CTDB_SERVICE_NMB=SERVICE
Distribution specific SERVICE for managing nmbd.
Default is distribution-dependant.
49.winbind
Provides CTDB's Samba winbind service management.
CTDB_SERVICE_WINBIND=SERVICE
Distribution specific SERVICE for managing winbindd.
Default is "winbind".
50.samba
Provides the core of CTDB's Samba file service management.
CTDB_SAMBA_CHECK_PORTS=PORT-LIST
When monitoring Samba, check TCP ports in
space-separated PORT-LIST.
Default is to monitor ports that Samba is configured to listen on.
CTDB_SAMBA_SKIP_SHARE_CHECK=yes|no
As part of monitoring, should CTDB skip the check for
the existence of each directory configured as share in
Samba. This may be desirable if there is a large number
of shares.
Default is no.
CTDB_SERVICE_SMB=SERVICE
Distribution specific SERVICE for managing smbd.
Default is distribution-dependant.
60.nfs
This event script (along with 06.nfs) provides CTDB's NFS
service management.
This includes parameters for the kernel NFS server.
Alternative NFS subsystems (such as NFS-Ganesha)
can be integrated using CTDB_NFS_CALLOUT.
CTDB_NFS_CALLOUT=COMMAND
COMMAND specifies the path to a callout to handle
interactions with the configured NFS system, including
startup, shutdown, monitoring.
Default is the included
nfs-linux-kernel-callout.
CTDB_NFS_CHECKS_DIR=DIRECTORY
Specifies the path to a DIRECTORY containing files that
describe how to monitor the responsiveness of NFS RPC
services. See the README file for this directory for an
explanation of the contents of these "check" files.
CTDB_NFS_CHECKS_DIR can be used to point to different
sets of checks for different NFS servers.
One way of using this is to have it point to, say,
/usr/local/etc/ctdb/nfs-checks-enabled.d
and populate it with symbolic links to the desired check
files. This avoids duplication and is upgrade-safe.
Default is
/usr/local/etc/ctdb/nfs-checks.d,
which contains NFS RPC checks suitable for Linux kernel
NFS.
CTDB_NFS_SKIP_SHARE_CHECK=yes|no
As part of monitoring, should CTDB skip the check for
the existence of each directory exported via NFS. This
may be desirable if there is a large number of exports.
Default is no.
CTDB_RPCINFO_LOCALHOST=IPADDR|HOSTNAME
IPADDR or HOSTNAME indicates the address that
rpcinfo should connect to when doing
rpcinfo check on IPv4 RPC service during
monitoring. Optimally this would be "localhost".
However, this can add some performance overheads.
Default is "127.0.0.1".
CTDB_RPCINFO_LOCALHOST6=IPADDR|HOSTNAME
IPADDR or HOSTNAME indicates the address that
rpcinfo should connect to when doing
rpcinfo check on IPv6 RPC service
during monitoring. Optimally this would be "localhost6"
(or similar). However, this can add some performance
overheads.
Default is "::1".
CTDB_NFS_STATE_FS_TYPE=TYPE
The type of filesystem used for a clustered NFS' shared
state. No default.
CTDB_NFS_STATE_MNT=DIR
The directory where a clustered NFS' shared state will be
located. No default.
70.iscsi
Provides CTDB's Linux iSCSI tgtd service management.
CTDB_START_ISCSI_SCRIPTS=DIRECTORY
DIRECTORY on shared storage containing scripts to start
tgtd for each public IP address.
No default.
DATABASE SETUP
CTDB checks the consistency of databases during startup.
00.ctdb
CTDB_MAX_CORRUPT_DB_BACKUPS=NUM
NUM is the maximum number of volatile TDB database
backups to be kept (for each database) when a corrupt
database is found during startup. Volatile TDBs are
zeroed during startup so backups are needed to debug
any corruption that occurs before a restart.
Default is 10.
SYSTEM RESOURCE MONITORING
05.system
Provides CTDB's filesystem and memory usage monitoring.
CTDB can experience seemingly random (performance and other)
issues if system resources become too constrained. Options in
this section can be enabled to allow certain system resources
to be checked. They allows warnings to be logged and nodes to
be marked unhealthy when system resource usage reaches the
configured thresholds.
Some checks are enabled by default. It is recommended that
these checks remain enabled or are augmented by extra checks.
There is no supported way of completely disabling the checks.
CTDB_MONITOR_FILESYSTEM_USAGE=FS-LIMIT-LIST
FS-LIMIT-LIST is a space-separated list of
FILESYSTEM:WARN_LIMIT:UNHEALTHY_LIMIT
triples indicating that warnings should be logged if the
space used on FILESYSTEM reaches WARN_LIMIT%. If usage
reaches UNHEALTHY_LIMIT then the node should be flagged
unhealthy. Either WARN_LIMIT or UNHEALTHY_LIMIT may be
left blank, meaning that check will be omitted.
Default is to warn for each filesystem containing a
database directory
(volatile database directory,
persistent database directory,
state database directory)
with a threshold of 90%.
CTDB_MONITOR_MEMORY_USAGE=MEM-LIMITS
MEM-LIMITS takes the form
WARN_LIMIT:UNHEALTHY_LIMIT
indicating that warnings should be logged if memory
usage reaches WARN_LIMIT%. If usage reaches
UNHEALTHY_LIMIT then the node should be flagged
unhealthy. Either WARN_LIMIT or UNHEALTHY_LIMIT may be
left blank, meaning that check will be omitted.
Default is 80, so warnings will be logged when memory
usage reaches 80%.
EVENT SCRIPT DEBUGGING
debug-hung-script.sh
CTDB_DEBUG_HUNG_SCRIPT_STACKPAT=REGEXP
REGEXP specifies interesting processes for which stack
traces should be logged when debugging hung eventscripts
and those processes are matched in pstree output.
REGEXP is an extended regexp so choices are separated by
pipes ('|'). However, REGEXP should not contain
parentheses. See also the ctdb.conf
5
[event] "debug script" option.
Default is "exportfs|rpcinfo".
FILES
/usr/local/etc/ctdb/script.options
SEE ALSO
ctdbd
1,
ctdb
7,
This documentation was written by
Amitay Isaacs,
Martin Schwenke
2007
Andrew Tridgell
Ronnie Sahlberg
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public
License along with this program; if not, see
.