Module: NODE

Module: NODE

Mange nodes in a declarative manner

Concept

Node is an abstraction of hardware resources, which can be bare metal, virtual machines, or even k8s pods.

There are different types of nodes in Pigsty:

Common nodes, nodes that managed by Pigsty
Admin node, the node where pigsty is installed and issue admin commands
The Infra node, the node where the INFRA module is installed, admin node are usually the first of all infra nodes.

Common Node

You can manage nodes with Pigsty, and install modules on them. The node.yml playbook will adjust the node to desired state.

Some services will be added to all nodes by default:

Component	Port	Description
Node Exporter	9100	Node Monitoring Metrics Exporter
HAProxy Admin	9101	HAProxy admin page
Promtail	9080	Log collecting agent

Admin Node

There is one and only one admin node in a pigsty deployment, which is specified by admin_ip. It is set to the local primary IP during configure.

The node will have ssh / sudo access to all other nodes, which is critical; ensure it’s fully secured.

INFRA Node

A pigsty deployment may have one or more infra nodes, usually 2 ~ 3, in a large production environment.

The infra group specifies infra nodes in the inventory. And infra nodes will have INFRA module installed (DNS, Nginx, Prometheus, Grafana, etc…),

The admin node is also the default and first infra node, and infra nodes can be used as ‘backup’ admin nodes.

PGSQL Node

The node with PGSQL module installed is called a PGSQL node. The node and pg instance is 1:1 deployed. And node instance can be borrowed from corresponding pg instances with node_id_from_pg.

Component	Port	Description
Postgres	5432	Pigsty CMDB
Pgbouncer	6432	Pgbouncer Connection Pooling Service
Patroni	8008	Patroni HA Component
Haproxy Primary	5433	Primary connection pool: Read/Write Service
Haproxy Replica	5434	Replica connection pool: Read-only Service
Haproxy Default	5436	Primary Direct Connect Service
Haproxy Offline	5438	Offline Direct Connect: Offline Read Service
Haproxy `service`	543x	Customized Services
Haproxy Admin	9101	Monitoring metrics and traffic management
PG Exporter	9630	PG Monitoring Metrics Exporter
PGBouncer Exporter	9631	PGBouncer Monitoring Metrics Exporter
Node Exporter	9100	Node Monitoring Metrics Exporter
Promtail	9080	Collection of Postgres, Pgbouncer, Patroni logs (Optional)
vip-manager	-	Bind VIP to the primary

Administration

Add Node

To add a node into Pigsty, you need to have nopass ssh/sudo access to the node

bin/node-add [ip...]      # add node to pigsty:  ./node.yml -l <cls|ip|group>

Remove Node

To remove a node from Pigsty, you can use the following:

bin/node-rm [ip...]       # remove node from pigsty: ./node-rm.yml -l <cls|ip|group>

Create Admin

If the current user does not have nopass ssh/sudo access to the node, you can use another admin user to bootstrap the node:

node.yml -t node_admin -k -K -e ansible_user=<another admin>   # input ssh/sudo password for another admin

Playbooks

node.yml : Init node for pigsty
node-rm.yml : Remove node from pigsty

Dashboards

There are four dashboards for NODE module.

NODE Overview: Overview of all nodes
NODE Cluster: Detail information about a node cluster
NODE Instance: Detail information about a Node instance
NODE HAProxy: Detail information about haproxy service on the node

Parameters

There are 9 sections, 58 parameters about NODE module.

NODE_ID : Node identity parameters
NODE_DNS : Node Domain Name Resolution
NODE_PACKAGE : Upstream Repo & Install Packages
NODE_TUNE : Node Tuning & Features
NODE_ADMIN : Admin User & SSH Keys
NODE_TIME : Timezone, NTP, Crontab
HAPROXY : Expose services with HAProxy
NODE_EXPORTER : Node monitoring agent
PROMTAIL : Promtail logging agent

Parameters

Parameter	Section	Type	Level	Comment
nodename	NODE_ID	string	I	node instance identity, use hostname if missing, optional
node_cluster	NODE_ID	string	C	node cluster identity, use ’nodes’ if missing, optional
nodename_overwrite	NODE_ID	bool	C	overwrite node’s hostname with nodename?
nodename_exchange	NODE_ID	bool	C	exchange nodename among play hosts?
node_id_from_pg	NODE_ID	bool	C	use postgres identity as node identity if applicable?
node_default_etc_hosts	NODE_DNS	string[]	G	static dns records in `/etc/hosts`
node_etc_hosts	NODE_DNS	string[]	C	extra static dns records in `/etc/hosts`
node_dns_method	NODE_DNS	enum	C	how to handle dns servers: add,none,overwrite
node_dns_servers	NODE_DNS	string[]	C	dynamic nameserver in `/etc/resolv.conf`
node_dns_options	NODE_DNS	string[]	C	dns resolv options in `/etc/resolv.conf`
node_repo_method	NODE_PACKAGE	enum	C	how to setup node repo: none,local,public
node_repo_remove	NODE_PACKAGE	bool	C	remove existing repo on node?
node_repo_local_urls	NODE_PACKAGE	string[]	C	local repo url, if node_repo_method = local
node_packages	NODE_PACKAGE	string[]	C	packages to be installed current nodes
node_default_packages	NODE_PACKAGE	string[]	G	default packages to be installed on all nodes
node_disable_firewall	NODE_TUNE	bool	C	disable node firewall? true by default
node_disable_selinux	NODE_TUNE	bool	C	disable node selinux? true by default
node_disable_numa	NODE_TUNE	bool	C	disable node numa, reboot required
node_disable_swap	NODE_TUNE	bool	C	disable node swap, use with caution
node_static_network	NODE_TUNE	bool	C	preserve dns resolver settings after reboot
node_disk_prefetch	NODE_TUNE	bool	C	setup disk prefetch on HDD to increase performance
node_kernel_modules	NODE_TUNE	string[]	C	kernel modules to be enabled on this node
node_hugepage_count	NODE_TUNE	int	C	number of 2MB hugepage, take precedence over ratio
node_hugepage_ratio	NODE_TUNE	float	C	node mem hugepage ratio, 0 disable it by default
node_overcommit_ratio	NODE_TUNE	int	C	node mem overcommit ratio (50-100), 0 disable it by default
node_tune	NODE_TUNE	enum	C	node tuned profile: none,oltp,olap,crit,tiny
node_sysctl_params	NODE_TUNE	dict	C	sysctl parameters in k:v format in addition to tuned
node_data	NODE_ADMIN	path	C	node main data directory, `/data` by default
node_admin_enabled	NODE_ADMIN	bool	C	create a admin user on target node?
node_admin_uid	NODE_ADMIN	int	C	uid and gid for node admin user
node_admin_username	NODE_ADMIN	username	C	name of node admin user, `dba` by default
node_admin_ssh_exchange	NODE_ADMIN	bool	C	exchange admin ssh key among node cluster
node_admin_pk_current	NODE_ADMIN	bool	C	add current user’s ssh pk to admin authorized_keys
node_admin_pk_list	NODE_ADMIN	string[]	C	ssh public keys to be added to admin user
node_timezone	NODE_TIME	string	C	setup node timezone, empty string to skip
node_ntp_enabled	NODE_TIME	bool	C	enable chronyd time sync service?
node_ntp_servers	NODE_TIME	string[]	C	ntp servers in `/etc/chrony.conf`
node_crontab_overwrite	NODE_TIME	bool	C	overwrite or append to `/etc/crontab`?
node_crontab	NODE_TIME	string[]	C	crontab entries in `/etc/crontab`
haproxy_enabled	HAPROXY	bool	C	enable haproxy on this node?
haproxy_clean	HAPROXY	bool	G/C/A	cleanup all existing haproxy config?
haproxy_reload	HAPROXY	bool	A	reload haproxy after config?
haproxy_auth_enabled	HAPROXY	bool	G	enable authentication for haproxy admin page
haproxy_admin_username	HAPROXY	username	G	haproxy admin username, `admin` by default
haproxy_admin_password	HAPROXY	password	G	haproxy admin password, `pigsty` by default
haproxy_exporter_port	HAPROXY	port	C	haproxy admin/exporter port, 9101 by default
haproxy_client_timeout	HAPROXY	interval	C	client side connection timeout, 24h by default
haproxy_server_timeout	HAPROXY	interval	C	server side connection timeout, 24h by default
haproxy_services	HAPROXY	service[]	C	list of haproxy service to be exposed on node
node_exporter_enabled	NODE_EXPORTER	bool	C	setup node_exporter on this node?
node_exporter_port	NODE_EXPORTER	port	C	node exporter listen port, 9100 by default
node_exporter_options	NODE_EXPORTER	arg	C	extra server options for node_exporter
promtail_enabled	PROMTAIL	bool	C	enable promtail logging collector?
promtail_clean	PROMTAIL	bool	G/A	purge existing promtail status file during init?
promtail_port	PROMTAIL	port	C	promtail listen port, 9080 by default
promtail_positions	PROMTAIL	path	C	promtail position status file path

Last modified 2023-02-27: add v2.0 images and docs (5b09f12)