YARN-7201. Added an apache httpd example YARN service. Contributed by Billie Rinaldi

This commit is contained in:
Jian He 2017-09-25 16:36:43 -07:00
parent ce74e64363
commit c70e5df100
10 changed files with 367 additions and 1 deletions

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@ -0,0 +1,62 @@
{
"name": "httpd-service-no-dns",
"lifetime": "3600",
"components": [
{
"name": "httpd",
"number_of_containers": 2,
"artifact": {
"id": "centos/httpd-24-centos7:latest",
"type": "DOCKER"
},
"launch_command": "/usr/bin/run-httpd",
"resource": {
"cpus": 1,
"memory": "1024"
},
"readiness_check": {
"type": "HTTP",
"props": {
"url": "http://${THIS_HOST}:8080"
}
},
"configuration": {
"files": [
{
"type": "ENV",
"dest_file": "/var/www/html/index.html",
"props": {
"content": "<html><header><title>Title</title></header><body>Hello from ${COMPONENT_INSTANCE_NAME}!</body></html>"
}
}
]
}
},
{
"name": "httpd-proxy",
"number_of_containers": 1,
"dependencies": [ "httpd" ],
"artifact": {
"id": "centos/httpd-24-centos7:latest",
"type": "DOCKER"
},
"launch_command": "/usr/bin/run-httpd",
"resource": {
"cpus": 1,
"memory": "1024"
},
"configuration": {
"files": [
{
"type": "TEMPLATE",
"dest_file": "/etc/httpd/conf.d/httpd-proxy.conf",
"src_file": "httpd-proxy-no-dns.conf"
}
]
}
}
],
"quicklinks": {
"Apache HTTP Server": "http://httpd-proxy-0.${SERVICE_NAME}.${USER}.${DOMAIN}:8080"
}
}

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@ -0,0 +1,24 @@
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
<Proxy balancer://test>
BalancerMember http://${HTTPD-0_IP}:8080
BalancerMember http://${HTTPD-1_IP}:8080
ProxySet lbmethod=bytraffic
</Proxy>
ProxyPass "/" "balancer://test/"
ProxyPassReverse "/" "balancer://test/"

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@ -0,0 +1,24 @@
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
<Proxy balancer://test>
BalancerMember http://httpd-0.${SERVICE_NAME}.${USER}.${DOMAIN}:8080
BalancerMember http://httpd-1.${SERVICE_NAME}.${USER}.${DOMAIN}:8080
ProxySet lbmethod=bytraffic
</Proxy>
ProxyPass "/" "balancer://test/"
ProxyPassReverse "/" "balancer://test/"

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@ -0,0 +1,55 @@
{
"name": "httpd-service",
"lifetime": "3600",
"components": [
{
"name": "httpd",
"number_of_containers": 2,
"artifact": {
"id": "centos/httpd-24-centos7:latest",
"type": "DOCKER"
},
"launch_command": "/usr/bin/run-httpd",
"resource": {
"cpus": 1,
"memory": "1024"
},
"configuration": {
"files": [
{
"type": "ENV",
"dest_file": "/var/www/html/index.html",
"props": {
"content": "<html><header><title>Title</title></header><body>Hello from ${COMPONENT_INSTANCE_NAME}!</body></html>"
}
}
]
}
},
{
"name": "httpd-proxy",
"number_of_containers": 1,
"artifact": {
"id": "centos/httpd-24-centos7:latest",
"type": "DOCKER"
},
"launch_command": "/usr/bin/run-httpd",
"resource": {
"cpus": 1,
"memory": "1024"
},
"configuration": {
"files": [
{
"type": "TEMPLATE",
"dest_file": "/etc/httpd/conf.d/httpd-proxy.conf",
"src_file": "httpd-proxy.conf"
}
]
}
}
],
"quicklinks": {
"Apache HTTP Server": "http://httpd-proxy-0.${SERVICE_NAME}.${USER}.${DOMAIN}:8080"
}
}

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@ -52,6 +52,11 @@ public interface ServiceApiConstants {
String CONTAINER_ID = $("CONTAINER_ID");
// Templates for component instance host/IP
String COMPONENT_HOST = $("%s_HOST");
String COMPONENT_IP = $("%s_IP");
// Constants for default cluster ZK
String CLUSTER_ZK_QUORUM = $("CLUSTER_ZK_QUORUM");

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@ -47,8 +47,10 @@ import org.slf4j.LoggerFactory;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
@ -58,6 +60,7 @@ import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import static org.apache.hadoop.yarn.api.records.ContainerExitStatus.*;
import static org.apache.hadoop.yarn.service.api.ServiceApiConstants.*;
import static org.apache.hadoop.yarn.service.component.ComponentEventType.*;
import static org.apache.hadoop.yarn.service.component.instance.ComponentInstanceEventType.START;
import static org.apache.hadoop.yarn.service.component.instance.ComponentInstanceEventType.STOP;
@ -386,6 +389,34 @@ public class Component implements EventHandler<ComponentEvent> {
return true;
}
public Map<String, String> getDependencyHostIpTokens() {
Map<String, String> tokens = new HashMap<>();
List<String> dependencies = componentSpec.getDependencies();
if (SliderUtils.isEmpty(dependencies)) {
return tokens;
}
for (String dependency : dependencies) {
Collection<ComponentInstance> instances = scheduler.getAllComponents()
.get(dependency).getAllComponentInstances().values();
for (ComponentInstance instance : instances) {
if (instance.getContainerStatus() == null) {
continue;
}
if (SliderUtils.isEmpty(instance.getContainerStatus().getIPs()) ||
SliderUtils.isUnset(instance.getContainerStatus().getHost())) {
continue;
}
String ip = instance.getContainerStatus().getIPs().get(0);
String host = instance.getContainerStatus().getHost();
tokens.put(String.format(COMPONENT_IP,
instance.getCompInstanceName().toUpperCase()), ip);
tokens.put(String.format(COMPONENT_HOST,
instance.getCompInstanceName().toUpperCase()), host);
}
}
return tokens;
}
private void incRunningContainers() {
componentMetrics.containersRunning.incr();
scheduler.getServiceMetrics().containersRunning.incr();

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@ -397,6 +397,7 @@ public class ProviderUtils implements YarnServiceConstants {
tokens.put(CONTAINER_ID, instance.getContainer().getId().toString());
tokens.put(COMPONENT_ID,
String.valueOf(instance.getCompInstanceId().getId()));
tokens.putAll(instance.getComponent().getDependencyHostIpTokens());
return tokens;
}
}

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@ -1550,6 +1550,10 @@ public class RegistryDNS extends AbstractService implements DNSOperations,
private final RegistryCommand removeRecordCommand = new RegistryCommand() {
@Override
public void exec(Zone zone, Record record) throws IOException {
if (zone == null) {
LOG.error("Unable to remove record because zone is null: {}", record);
return;
}
zone.removeRecord(record);
LOG.info("Removed {}", record);
if (isDNSSECEnabled()) {

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@ -0,0 +1,159 @@
<!---
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. See accompanying LICENSE file.
-->
# YARN Service Examples
This document describes some example service definitions (`Yarnfile`).
<!-- MACRO{toc|fromDepth=0|toDepth=3} -->
## Apache web server - httpd (with registry DNS)
Below is the `Yarnfile` for a service called `httpd-service` with two `httpd` instances.
There is also an httpd proxy instance (httpd-proxy-0) that proxies between the other two httpd instances (httpd-0 and httpd-1).
Note this example requires registry DNS.
```
{
"name": "httpd-service",
"lifetime": "3600",
"components": [
{
"name": "httpd",
"number_of_containers": 2,
"artifact": {
"id": "centos/httpd-24-centos7:latest",
"type": "DOCKER"
},
"launch_command": "/usr/bin/run-httpd",
"resource": {
"cpus": 1,
"memory": "1024"
},
"configuration": {
"files": [
{
"type": "ENV",
"dest_file": "/var/www/html/index.html",
"props": {
"content": "<html><header><title>Title</title></header><body>Hello from ${COMPONENT_INSTANCE_NAME}!</body></html>"
}
}
]
}
},
{
"name": "httpd-proxy",
"number_of_containers": 1,
"artifact": {
"id": "centos/httpd-24-centos7:latest",
"type": "DOCKER"
},
"launch_command": "/usr/bin/run-httpd",
"resource": {
"cpus": 1,
"memory": "1024"
},
"configuration": {
"files": [
{
"type": "TEMPLATE",
"dest_file": "/etc/httpd/conf.d/httpd-proxy.conf",
"src_file": "httpd-proxy.conf"
}
]
}
}
],
"quicklinks": {
"Apache HTTP Server": "http://httpd-proxy-0.${SERVICE_NAME}.${USER}.${DOMAIN}:8080"
}
}
```
This `Yarnfile` is already included in the Hadoop distribution, along with the required configuration template `httpd-proxy.conf`.
First upload the configuration template file to HDFS:
```
hdfs dfs -copyFromLocal ${HADOOP_YARN_HOME}/share/hadoop/yarn/yarn-service-examples/httpd/httpd-proxy.conf .
```
The proxy configuration template looks like the following and will configure the httpd-proxy-0 container to balance between the httpd-0 and httpd-1 containers evenly:
```
<Proxy balancer://test>
BalancerMember http://httpd-0.${SERVICE_NAME}.${USER}.${DOMAIN}:8080
BalancerMember http://httpd-1.${SERVICE_NAME}.${USER}.${DOMAIN}:8080
ProxySet lbmethod=bytraffic
</Proxy>
ProxyPass "/" "balancer://test/"
ProxyPassReverse "/" "balancer://test/"
```
Then run the service with the command:
```
yarn service create [service-name] --example httpd
```
where `service-name` is optional. If omitted, it uses the name defined in the `Yarnfile`.
Once the service is running, navigate to `http://httpd-proxy-0.${SERVICE_NAME}.${USER}.${DOMAIN}:8080` to see the root page.
The pages should alternately show "Hello from httpd-0!" or "Hello from httpd-1!"
The individual httpd URLs can also be visited, `http://httpd-0.${SERVICE_NAME}.${USER}.${DOMAIN}:8080` and `http://httpd-1.${SERVICE_NAME}.${USER}.${DOMAIN}:8080`.
If unsure of your hostnames, visit the apiserver REST endpoint `http://<apiserver host>:9191/ws/v1/services/httpd-service`.
## Apache web server - httpd (without registry DNS)
A similar IP-based example is provided for environments that do not have registry DNS set up.
The service name for this example is `httpd-service-no-dns`.
There are a couple of additions to the `Yarnfile` for the `httpd-service` described above.
A readiness check is added for the `httpd` component:
```
"readiness_check": {
"type": "HTTP",
"props": {
"url": "http://${THIS_HOST}:8080"
}
},
```
and `httpd` is added as a dependency for the `httpd-proxy` component:
```
"dependencies": [ "httpd" ],
```
This means that the httpd-proxy-0 instance will not be started until after an HTTP probe has succeeded for the httpd-0 and httpd-1 containers.
This is necessary so that the IPs of the containers can be used in the configuration of httpd-proxy-0.
The proxy configuration is similar to that of the previous example, with the BalancerMember lines changed as follows:
```
BalancerMember http://${HTTPD-0_IP}:8080
BalancerMember http://${HTTPD-1_IP}:8080
```
Note that IP and HOST variables such as `${HTTPD-0_IP}` and `${HTTPD-0_HOST}` should only be used by a component that has a dependency on the named component (`httpd` in this case) AND should only be used when the named component specifies a readiness check.
Here, `httpd-proxy` has a dependency on `httpd` and `httpd` has an HTTP readiness check.
Without the dependency and readiness check, the httpd-proxy-0 container would be started in parallel with the httpd-0 and http-1 containers, and the IPs and hosts would not be assigned yet for httpd-0 and httpd-1.
Other variables can be used by any component.
Before creating the service, upload the proxy configuration to HDFS:
```
hdfs dfs -copyFromLocal ${HADOOP_YARN_HOME}/share/hadoop/yarn/yarn-service-examples/httpd-no-dns/httpd-proxy-no-dns.conf .
```
Then run the service with the command:
```
yarn service create [service-name] --example httpd-no-dns
```
where `service-name` is optional. If omitted, it uses the name defined in the `Yarnfile`.
Look up your IPs at the apiserver REST endpoint `http://<apiserver host>:9191/ws/v1/services/httpd-service`.
Then visit port 8080 for each IP to view the pages.

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@ -52,7 +52,8 @@ The benefits of combining these workloads are two-fold:
* [Concepts](Concepts.md): Describes the internals of the framework and some features in YARN core to support running services on YARN.
* [Service REST API](YarnServiceAPI.md): The API doc for deploying/managing services on YARN.
* [Service Discovery](ServiceDiscovery.md): Deep dives into the YARN DNS internals
* [Service Discovery](ServiceDiscovery.md): Deep dives into the YARN DNS internals.
* [Examples](Examples.md): List some example service definitions (`Yarnfile`).