1PG_AUTOCTL CREATE POSTGRES(1) pg_auto_failover PG_AUTOCTL CREATE POSTGRES(1)
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6 pg_autoctl create postgres - pg_autoctl create postgres
7 pg_autoctl create postgres - Initialize a pg_auto_failover postgres
9 node
10
12 The command pg_autoctl create postgres initializes a standalone Post‐
13 gres node to a pg_auto_failover monitor. The monitor is then handling
14 auto-failover for this Postgres node (as soon as a secondary has been
15 registered too, and is known to be healthy).
16 usage: pg_autoctl create postgres
18 --pgctl path to pg_ctl
20 --pgdata path to data directory
21 --pghost PostgreSQL's hostname
22 --pgport PostgreSQL's port number
23 --listen PostgreSQL's listen_addresses
24 --username PostgreSQL's username
25 --dbname PostgreSQL's database name
26 --name pg_auto_failover node name
27 --hostname hostname used to connect from the other nodes
28 --formation pg_auto_failover formation
29 --monitor pg_auto_failover Monitor Postgres URL
30 --auth authentication method for connections from monitor
31 --skip-pg-hba skip editing pg_hba.conf rules
32 --pg-hba-lan edit pg_hba.conf rules for --dbname in detected LAN
33 --ssl-self-signed setup network encryption using self signed certificates (does NOT protect against MITM)
34 --ssl-mode use that sslmode in connection strings
35 --ssl-ca-file set the Postgres ssl_ca_file to that file path
36 --ssl-crl-file set the Postgres ssl_crl_file to that file path
37 --no-ssl don't enable network encryption (NOT recommended, prefer --ssl-self-signed)
38 --server-key set the Postgres ssl_key_file to that file path
39 --server-cert set the Postgres ssl_cert_file to that file path
40 --candidate-priority priority of the node to be promoted to become primary
41 --replication-quorum true if node participates in write quorum
42 --maximum-backup-rate maximum transfer rate of data transferred from the server during initial sync
43
45 Three different modes of initialization are supported by this command,
46 corresponding to as many implementation strategies.
47 1. Initialize a primary node from scratch
49 This happens when --pgdata (or the environment variable PGDATA)
51 points to an non-existing or empty directory. Then the given
52 --hostname is registered to the pg_auto_failover --monitor as a
53 member of the --formation.
54 The monitor answers to the registration call with a state to as‐
56 sign to the new member of the group, either SINGLE or
57 WAIT_STANDBY. When the assigned state is SINGLE, then pg_autoctl
58 create postgres proceedes to initialize a new PostgreSQL in‐
59 stance.
60 2. Initialize an already existing primary server
62 This happens when --pgdata (or the environment variable PGDATA)
64 points to an already existing directory that belongs to a Post‐
65 greSQL instance. The standard PostgreSQL tool pg_controldata is
66 used to recognize whether the directory belongs to a PostgreSQL
67 instance.
68 In that case, the given --hostname is registered to the monitor
70 in the tentative SINGLE state. When the given --formation and
71 --group is currently empty, then the monitor accepts the regis‐
72 tration and the pg_autoctl create prepares the already existing
73 primary server for pg_auto_failover.
74 3. Initialize a secondary node from scratch
76 This happens when --pgdata (or the environment variable PGDATA)
78 points to a non-existing or empty directory, and when the monitor
79 registration call assigns the state WAIT_STANDBY in step 1.
80 In that case, the pg_autoctl create command steps through the
82 initial states of registering a secondary server, which includes
83 preparing the primary server PostgreSQL HBA rules and creating a
84 replication slot.
85 When the command ends successfully, a PostgreSQL secondary server
87 has been created with pg_basebackup and is now started, catch‐
88 ing-up to the primary server.
89 4. Initialize a secondary node from an existing data directory
91 When the data directory pointed to by the option --pgdata or the
93 environment variable PGDATA already exists, then pg_auto_failover
94 verifies that the system identifier matches the one of the other
95 nodes already existing in the same group.
96 The system identifier can be obtained with the command pg_con‐
98 troldata. All nodes in a physical replication setting must have
99 the same system identifier, and so in pg_auto_failover all the
100 nodes in a same group have that constraint too.
101 When the system identifier matches the already registered system
103 identifier of other nodes in the same group, then the node is
104 set-up as a standby and Postgres is started with the primary con‐
105 ninfo pointed at the current primary.
106 The --auth option allows setting up authentication method to be used
108 when monitor node makes a connection to data node with pgauto‐
109 failover_monitor user. As with the pg_autoctl_create_monitor command,
110 you could use --auth trust when playing with pg_auto_failover at first
111 and consider something production grade later. Also, consider using
112 --skip-pg-hba if you already have your own provisioning tools with a
113 security compliance process.
114 See security for notes on .pgpass
116
118 The following options are available to pg_autoctl create postgres:
119 --pgctl
121 Path to the pg_ctl tool to use for the version of PostgreSQL you
122 want to use.
123 Defaults to the pg_ctl found in the PATH when there is a single
125 entry for pg_ctl in the PATH. Check your setup using which -a
126 pg_ctl.
127 When using an RPM based distribution such as RHEL or CentOS, the
129 path would usually be /usr/pgsql-13/bin/pg_ctl for Postgres 13.
130 When using a debian based distribution such as debian or ubuntu,
132 the path would usually be /usr/lib/postgresql/13/bin/pg_ctl for
133 Postgres 13. Those distributions also use the package post‐
134 gresql-common which provides /usr/bin/pg_config. This tool can
135 be automatically used by pg_autoctl to discover the default ver‐
136 sion of Postgres to use on your setup.
137 --pgdata
139 Location where to initialize a Postgres database cluster, using
140 either pg_ctl initdb or pg_basebackup. Defaults to the environ‐
141 ment variable PGDATA.
142 --pghost
144 Hostname to use when connecting to the local Postgres instance
145 from the pg_autoctl process. By default, this field is left
146 blank in the connection string, allowing to use Unix Domain
147 Sockets with the default path compiled in your libpq version,
148 usually provided by the Operating System. That would be
149 /var/run/postgresql when using debian or ubuntu.
150 --pgport
152 Postgres port to use, defaults to 5432.
153 --listen
155 PostgreSQL's listen_addresses to setup. At the moment only one
156 address is supported in this command line option.
157 --username
159 PostgreSQL's username to use when connecting to the local Post‐
160 gres instance to manage it.
161 --dbname
163 PostgreSQL's database name to use in your application. Defaults
164 to being the same as the --username, or to postgres when none of
165 those options are used.
166 --name Node name used on the monitor to refer to this node. The host‐
168 name is a technical information, and given Postgres requirements
169 on the HBA setup and DNS resolution (both forward and reverse
170 lookups), IP addresses are often used for the hostname.
171 The --name option allows using a user-friendly name for your
173 Postgres nodes.
174 --hostname
176 Hostname or IP address (both v4 and v6 are supported) to use
177 from any other node to connect to this node.
178 When not provided, a default value is computed by running the
180 following algorithm.
181 1. We get this machine's "public IP" by opening a connection
183 to the given monitor hostname or IP address. Then we get
184 TCP/IP client address that has been used to make that con‐
185 nection.
186 2. We then do a reverse DNS lookup on the IP address found in
188 the previous step to fetch a hostname for our local ma‐
189 chine.
190 3. If the reverse DNS lookup is successful , then pg_autoctl
192 does a forward DNS lookup of that hostname.
193 When the forward DNS lookup response in step 3. is an IP address
195 found in one of our local network interfaces, then pg_autoctl
196 uses the hostname found in step 2. as the default --hostname.
197 Otherwise it uses the IP address found in step 1.
198 You may use the --hostname command line option to bypass the
200 whole DNS lookup based process and force the local node name to
201 a fixed value.
202 --formation
204 Formation to register the node into on the monitor. Defaults to
205 the default formation, that is automatically created in the mon‐
206 itor in the pg_autoctl_create_monitor command.
207 --monitor
209 Postgres URI used to connect to the monitor. Must use the au‐
210 toctl_node username and target the pg_auto_failover database
211 name. It is possible to show the Postgres URI from the monitor
212 node using the command pg_autoctl_show_uri.
213 --auth Authentication method used by pg_autoctl when editing the Post‐
215 gres HBA file to open connections to other nodes. No default
216 value, must be provided by the user. The value --trust is only a
217 good choice for testing and evaluation of pg_auto_failover, see
218 security for more information.
219 --skip-pg-hba
221 When this option is used then pg_autoctl refrains from any edit‐
222 ing of the Postgres HBA file. Please note that editing the HBA
223 file is still needed so that other nodes can connect using ei‐
224 ther read privileges or replication streaming privileges.
225 When --skip-pg-hba is used, pg_autoctl still outputs the HBA en‐
227 tries it needs in the logs, it only skips editing the HBA file.
228 --pg-hba-lan
230 When this option is used pg_autoctl determines the local IP ad‐
231 dress used to connect to the monitor, and retrieves its netmask,
232 and uses that to compute your local area network CIDR. This CIDR
233 is then opened for connections in the Postgres HBA rules.
234 For instance, when the monitor resolves to 192.168.0.1 and your
236 local Postgres node uses an inferface with IP address
237 192.168.0.2/255.255.255.0 to connect to the monitor, then the
238 LAN CIDR is computed to be 192.168.0.0/24.
239 --candidate-priority
241 Sets this node replication setting for candidate priority to the
242 given value (between 0 and 100) at node registration on the mon‐
243 itor. Defaults to 50.
244 --replication-quorum
246 Sets this node replication setting for replication quorum to the
247 given value (either true or false) at node registration on the
248 monitor. Defaults to true, which enables synchronous replica‐
249 tion.
250 --maximum-backup-rate
252 Sets the maximum transfer rate of data transferred from the
253 server during initial sync. This is used by pg_basebackup. De‐
254 faults to 100M.
255 --run Immediately run the pg_autoctl service after having created this
257 node.
258 --ssl-self-signed
260 Generate SSL self-signed certificates to provide network encryp‐
261 tion. This does not protect against man-in-the-middle kinds of
262 attacks. See security for more about our SSL settings.
263 --ssl-mode
265 SSL Mode used by pg_autoctl when connecting to other nodes, in‐
266 cluding when connecting for streaming replication.
267 --ssl-ca-file
269 Set the Postgres ssl_ca_file to that file path.
270 --ssl-crl-file
272 Set the Postgres ssl_crl_file to that file path.
273 --no-ssl
275 Don't enable network encryption. This is not recommended, prefer
276 --ssl-self-signed.
277 --server-key
279 Set the Postgres ssl_key_file to that file path.
280 --server-cert
282 Set the Postgres ssl_cert_file to that file path.
283
285 Microsoft
286
288 Copyright (c) Microsoft Corporation. All rights reserved.
2891.6 Nov 24, 2021 PG_AUTOCTL CREATE POSTGRES(1)