ETCD installation
Installed directly
Take the MAC system as an example, to describe two methods according to the first is very simple, is the MAC:
Install Homebrew. If you do not install Homebrew, you can view the installation package by using the following command
brew search etcd
# installation
brew install etcd
# check version
etcd --version
--enable-v2=true --enable-v2=true
etcd --enable-v2=true
Copy the codeHowever, the installation may fail in this way. When this fails, I will be reminded that the log does not have permission at present. Just execute the relevant command as prompted.
sudo chown -R $(whoami) /usr/local/var/log
Copy the codeThe source code to install
I personally recommend the following installation method:
ETCD_VER = v3.4.14
# choose either URL
GOOGLE_URL=https://storage.googleapis.com/etcd
GITHUB_URL=https://github.com/etcd-io/etcd/releases/download
DOWNLOAD_URL=${GOOGLE_URL}
rm -f /tmp/etcd-${ETCD_VER}-darwin-amd64.zip
rm -rf /tmp/etcd-download-test && mkdir -p /tmp/etcd-download-test
curl -L ${DOWNLOAD_URL}/${ETCD_VER}/etcd-${ETCD_VER}-darwin-amd64.zip -o /tmp/etcd-${ETCD_VER}-darwin-amd64.zip
unzip /tmp/etcd-${ETCD_VER}-darwin-amd64.zip -d /tmp && rm -f /tmp/etcd-${ETCD_VER}-darwin-amd64.zip
mv /tmp/etcd-${ETCD_VER}-darwin-amd64/* /tmp/etcd-download-test && rm -rf mv /tmp/etcd-${ETCD_VER}-darwin-amd64
Print the ETCD version
/tmp/etcd-download-test/etcd --version
/tmp/etcd-download-test/etcdctl version
Copy etcd and etcdctl to bin directory
cp /tmp/etcd-download-test/etcd /usr/local/bin
cp /tmp/etcd-download-test/etcdctl /usr/local/bin
Then execute:
# installation etcd
sh etcd_install.sh
# check version
etcd --version
--enable-v2=true --enable-v2=true
etcd --enable-v2=true
Copy the codeCluster deployment
Deployment process
The first script, which does not support pasting blocks outside Docs, reads as follows: https://www.cnblogs.com/linuxws/p/11194403.html) :
TOKEN=token-01
CLUSTER_STATE=new
NAME_1=etcd-01
NAME_2=etcd-02
NAME_3=etcd-03
HOST_1 = 127.0.0.1
HOST_2 = 127.0.0.1
HOST_3 = 127.0.0.1
PORT_API_1=2379
PORT_PEER_1=2380
PORT_API_2=2479
PORT_PEER_2=2480
PORT_API_3=2579
PORT_PEER_3=2580
CLUSTER=${NAME_1}=http://${HOST_1}:${PORT_PEER_1}.${NAME_2}=http://${HOST_2}:${PORT_PEER_2}.${NAME_3}=http://${HOST_3}:${PORT_PEER_3}
# For every machine
THIS_NAME=${NAME_1}
THIS_IP=${HOST_1}
THIS_PORT_API=${PORT_API_1}
THIS_PORT_PEER=${PORT_PEER_1}
# Used to kill processes
lsof -i:2379 | awk '{print $2}' | grep -v "PID" | uniq | xargs kill9 -
# --enable-v2 Supports the v2 interface and can be omitted
# --data-dir Data storage directory, can be omitted
# --name Specifies the node name
--initial-advertise-peer-urls Specifies the URL for data to interact with within the cluster
Listen-peer-urls Specifies the listening URL for communication between cluster nodes
# --advertise-client-urls This address is used by the client to communicate with this member
Listen for the url requested by the client
# --initial-cluster Specifies the initial cluster configuration
--initial-cluster-state Initializes the cluster state. The value can be new or existing
# --initial-cluster-token The cluster initializes the token and can be omitted
etcd --enable-v2=true --data-dir=data.${THIS_NAME} --name ${THIS_NAME} \
--initial-advertise-peer-urls http://${THIS_IP}:${THIS_PORT_PEER} --listen-peer-urls http://${THIS_IP}:${THIS_PORT_PEER} \
--advertise-client-urls http://${THIS_IP}:${THIS_PORT_API} --listen-client-urls http://${THIS_IP}:${THIS_PORT_API} \
--initial-cluster ${CLUSTER} \
--initial-cluster-state ${CLUSTER_STATE} --initial-cluster-token ${TOKEN}
Copy the codeThe second script needs to replace the contents with the following:
# For every machine
THIS_NAME=${NAME_2}
THIS_IP=${HOST_2}
THIS_PORT_API=${PORT_API_2}
THIS_PORT_PEER=${PORT_PEER_2}
# Used to kill processes
lsof -i:2479 | awk '{print $2}' | grep -v "PID" | uniq | xargs kill9 -
Copy the codeThe third script needs to be replaced with the following:
# For every machine
THIS_NAME=${NAME_3}
THIS_IP=${HOST_3}
THIS_PORT_API=${PORT_API_3}
THIS_PORT_PEER=${PORT_PEER_3}
# Used to kill processes
lsof -i:2579 | awk '{print $2}' | grep -v "PID" | uniq | xargs kill9 -
Copy the codeWith these 3 scripts, 3 Windows were opened and executed respectively. The screenshot of service startup is as follows:
After all three scripts are started and the cluster deployment is complete, we check the health status of the three nodes:
The curl http://127.0.0.1:2379/health
The curl http://127.0.0.1:2479/health
The curl http://127.0.0.1:2579/health
Copy the codeIf {“health”:”true”} is returned, the deployment is successful.
The curl http://127.0.0.1:2379/v2/members
Copy the codeThe result is as follows, where peerURLs is the URL that the nodes communicate with each other and clientURLs is the URL that they access externally:
{
"members": [
{
"id":"264ae6bc59e99892".
"name":"etcd-01".
"peerURLs": [
"http://127.0.0.1:2380"
].
"clientURLs": [
"http://127.0.0.1:2379"
]
},
{
"id":"dbafe5ad6b652eda".
"name":"etcd-02".
"peerURLs": [
"http://127.0.0.1:2480"
].
"clientURLs": [
"http://127.0.0.1:2479"
]
},
{
"id":"f570ae41f524bdcb".
"name":"etcd-03".
"peerURLs": [
"http://127.0.0.1:2580"
].
"clientURLs": [
"http://127.0.0.1:2579"
]
}
]
}
Copy the codeHave a problem
Question 1: service starts, cannot use v2 interface, such as the execution “curl http://127.0.0.1:2379/v2/members,” tip “404 page not found”
Cause: V3.4 uses V3 ports by default and does not support V2
Solution: Add –enable-v2=true when you start etCD to force you to use the V2 interface
Question 2: Failed to start the service. Conflicting environment variable “ETCD_ENABLE_V2″ is Shadowed by corresponding command-line flag (either unset Environment variable or disable flag)”
Cause: The “–enable-v2=true” parameter is used when the ETCD is started. V3.4 will read the configuration, and a message is displayed indicating that the configuration is repeated.
Solution: Do not delete this parameter, otherwise it will introduce other problems, I just close all Windows and restart etCD.
Fault 3: When a node is started, a message is displayed indicating that member already exists
Cause: Because the node has been started before, the member already exists and cannot be initialized. Only existing members can be added
Solution: You need to change the startup script “CLUSTER_STATE=new” to “CLUSTER_STATE=existing”
Normal operation
Cluster management
Here’s a quick summary of the methods we use to deploy a cluster:
// Version check, output {"etcdserver":"3.4.14"."etcdcluster":"3.4.0"}
The curl http://127.0.0.1:2379/version
// Health check, output {"health":"true"}
The curl http://127.0.0.1:2379/health
// View cluster nodes
The curl http://127.0.0.1:2379/v2/members
Copy the codeThe key value actions
Set the key value:
The curl http://127.0.0.1:2379/v2/keys/message - XPUT - value = d"hello world"
Copy the codeReturn result:
{
"action":"set".
"node": {
"key":"/message".
"value":"hello world".
"modifiedIndex": 43.
"createdIndex"43:
}
}
Copy the codeRead key values:
The curl http://127.0.0.1:2379/v2/keys/message
Copy the codeReturn result:
{
"action":"get".
"node": {
"key":"/message".
"value":"hello world".
"modifiedIndex": 43.
"createdIndex"43:
}
}
Copy the codeSet key timeout to 10s:
The curl http://127.0.0.1:2379/v2/keys/message - XPUT - value = d"hello world" -d ttl=10
Copy the codeReturns the result (prevNode is old) :
{
"action":"set".
"node": {
"key":"/message".
"value":"hello world".
"expiration":"The 2021-01-21 T00: not. 777434 z".
"ttl": 10,
"modifiedIndex": 44,
"createdIndex"44:
},
"prevNode": {
"key":"/message".
"value":"hello world".
"modifiedIndex": 43.
"createdIndex"43:
}
}
Copy the codeKey not found = key not found = key not found
Watch notice
When the value of the key changes, the listening client will be notified. We will first listen on the key on client A:
The curl http://127.0.0.1:2379/v2/keys/message?wait=true
Copy the codeThen on client B, change the value of this key:
The curl http://127.0.0.1:2379/v2/keys/message - XPUT - value = d"hello world2"
Copy the codeClient A returns and exits with the result:
{
"action":"set".
"node": {
"key":"/message".
"value":"hello world2".
"modifiedIndex": 48.
"createdIndex"48:
}
}
Copy the codeIf you want client A to continue listening without exiting, you can add the stream=true argument:
curl "Http://127.0.0.1:2379/v2/keys/message? wait=true&stream=true"
Copy the codeWhen the following is executed on client B:
The curl http://127.0.0.1:2379/v2/keys/message - XPUT - value = d"hello world" -d ttl=10
Copy the codeClient A will listen to the return in real time. For example, when the key is set, or when the key expires, client A will listen to:
