NSQ
Since Camel 2.23
Both producer and consumer are supported
NSQ is a realtime distributed messaging platform.
Maven users will need to add the following dependency to
their pom.xml for this component.
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-nsq</artifactId>
<!-- use the same version as your Camel core version -->
<version>x.y.z</version>
</dependency>Configuring Options
Camel components are configured on two separate levels:
-
component level
-
endpoint level
Configuring Component Options
The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.
Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.
Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.
Configuring Endpoint Options
Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.
Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL as a type safe way of configuring endpoints.
A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.
The following two sections lists all the options, firstly for the component followed by the endpoint.
Component Options
The NSQ component supports 5 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
servers (common) |
The hostnames of one or more nsqlookupd servers (consumer) or nsqd servers (producer). |
String |
|
bridgeErrorHandler (consumer) |
Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. |
boolean |
|
lazyStartProducer (producer) |
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. |
boolean |
|
autowiredEnabled (advanced) |
Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. |
true |
boolean |
useGlobalSslContextParameters (security) |
Enable usage of global SSL context parameters. |
boolean |
Endpoint Options
The NSQ endpoint is configured using URI syntax:
nsq:topic
with the following path and query parameters:
Path Parameters (1 parameters)
| Name | Description | Default | Type |
|---|---|---|---|
topic (common) |
Required The NSQ topic. |
String |
Query Parameters (17 parameters)
| Name | Description | Default | Type |
|---|---|---|---|
servers (common) |
The hostnames of one or more nsqlookupd servers (consumer) or nsqd servers (producer). |
String |
|
userAgent (common) |
A String to identify the kind of client. |
String |
|
autoFinish (consumer) |
Automatically finish the NSQ Message when it is retrieved from the queue and before the Exchange is processed. |
true |
Boolean |
bridgeErrorHandler (consumer) |
Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. |
boolean |
|
channel (consumer) |
The NSQ channel. |
String |
|
customNSQLookup (consumer) |
A Custom NSQ lookup implementation. |
NSQLookup |
|
lookupInterval (consumer) |
The lookup interval. |
5000 |
long |
lookupServerPort (consumer) |
The NSQ lookup server port. |
4161 |
int |
messageTimeout (consumer) |
The NSQ consumer timeout period for messages retrieved from the queue. A value of -1 is the server default. |
-1 |
long |
poolSize (consumer) |
Consumer pool size. |
10 |
int |
requeueInterval (consumer) |
The requeue interval in milliseconds. A value of -1 is the server default. |
-1 |
long |
exceptionHandler (consumer (advanced)) |
To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored. |
ExceptionHandler |
|
exchangePattern (consumer (advanced)) |
Sets the exchange pattern when the consumer creates an exchange. Enum values:
|
ExchangePattern |
|
lazyStartProducer (producer) |
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. |
boolean |
|
port (producer) |
The port of the nsqd server. |
4150 |
int |
secure (security) |
Set secure option indicating TLS is required. |
boolean |
|
sslContextParameters (security) |
To configure security using SSLContextParameters. |
SSLContextParameters |
Examples
To send a message to a NSQ server
from("direct:start").to("nsq:myTopic?servers=myserver:4161");And to receive messages from NSQ
<route>
<from uri="nsq:myTopic?servers=myserver:4161"/>
<to uri="bean:doSomething"/>
</route>The server can be configured on the component level, for example if using Spring Boot in the application.properties file:
camel.component.nsq.servers=myserver1:4161,my-second-server:4161Then you can omit the servers from the endpoint URI
from("direct:start").to("nsq:myTopic");Spring Boot Auto-Configuration
When using nsq with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-nsq-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>The component supports 6 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
camel.component.nsq.autowired-enabled |
Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. |
true |
Boolean |
camel.component.nsq.bridge-error-handler |
Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. |
false |
Boolean |
camel.component.nsq.enabled |
Whether to enable auto configuration of the nsq component. This is enabled by default. |
Boolean |
|
camel.component.nsq.lazy-start-producer |
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. |
false |
Boolean |
camel.component.nsq.servers |
The hostnames of one or more nsqlookupd servers (consumer) or nsqd servers (producer). |
String |
|
camel.component.nsq.use-global-ssl-context-parameters |
Enable usage of global SSL context parameters. |
false |
Boolean |