Beanstalk
Since Camel 2.15
Both producer and consumer are supported
Camel Beanstalk project provides a Camel component for job retrieval and post-processing of Beanstalk jobs.
You can find the detailed explanation of Beanstalk job lifecycle at Beanstalk protocol.
Dependencies
Maven users need to add the following dependency to their pom.xml
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-beanstalk</artifactId>
<version>${camel-version}</version>
</dependency>
where ${camel-version
} must be replaced by the actual version of Camel.
URI format
beanstalk://[host[:port]][/tube][?options]
You may omit either port
or both host
and port
: for the Beanstalk
defaults to be used (“localhost” and 11300). If you omit tube
,
Beanstalk component will use the tube with name “default”.
When listening, you may probably want to watch for jobs from several tubes. Just separate them with plus sign, e.g.
beanstalk://localhost:11300/tube1+tube2
Tube name will be URL decoded, so if your tube names include special characters like + or ?, you need to URL-encode them appropriately, or use the RAW syntax, see more details here.
By the way, you cannot specify several tubes when you are writing jobs into Beanstalk.
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 Beanstalk component supports 4 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
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 |
|
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 |
|
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 |
|
Custom ConnectionSettingsFactory. <p/> Specify which ConnectionSettingsFactory to use to make connections to Beanstalkd. Especially useful for unit testing without beanstalkd daemon (you can mock ConnectionSettings). |
ConnectionSettingsFactory |
Endpoint Options
The Beanstalk endpoint is configured using URI syntax:
beanstalk:connectionSettings
with the following path and query parameters:
Query Parameters (27 parameters)
Name | Description | Default | Type |
---|---|---|---|
put means to put the job into Beanstalk. Job body is specified in the Camel message body. Job ID will be returned in beanstalk.jobId message header. delete, release, touch or bury expect Job ID in the message header beanstalk.jobId. Result of the operation is returned in beanstalk.result message header kick expects the number of jobs to kick in the message body and returns the number of jobs actually kicked out in the message header beanstalk.result. Enum values:
|
BeanstalkCommand |
||
Job delay in seconds. |
0 |
int |
|
Job priority. (0 is the highest, see Beanstalk protocol). |
1000 |
long |
|
Job time to run in seconds. (when 0, the beanstalkd daemon raises it to 1 automatically, see Beanstalk protocol). |
60 |
int |
|
Whether to wait for job to complete before ack the job from beanstalk. |
true |
boolean |
|
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 |
|
Command to use when processing failed. Enum values:
|
BeanstalkCommand |
||
If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead. |
false |
boolean |
|
Whether to use blockIO. |
true |
boolean |
|
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 |
||
Sets the exchange pattern when the consumer creates an exchange. Enum values:
|
ExchangePattern |
||
A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel. |
PollingConsumerPollStrategy |
||
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 |
|
The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in. |
int |
||
The number of subsequent idle polls that should happen before the backoffMultipler should kick-in. |
int |
||
To let the scheduled polling consumer backoff if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the next actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured. |
int |
||
Milliseconds before the next poll. |
500 |
long |
|
If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the previous run polled 1 or more messages. |
false |
boolean |
|
Milliseconds before the first poll starts. |
1000 |
long |
|
Specifies a maximum limit of number of fires. So if you set it to 1, the scheduler will only fire once. If you set it to 5, it will only fire five times. A value of zero or negative means fire forever. |
0 |
long |
|
The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that. Enum values:
|
TRACE |
LoggingLevel |
|
Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool. |
ScheduledExecutorService |
||
To use a cron scheduler from either camel-spring or camel-quartz component. Use value spring or quartz for built in scheduler. |
none |
Object |
|
To configure additional properties when using a custom scheduler or any of the Quartz, Spring based scheduler. |
Map |
||
Whether the scheduler should be auto started. |
true |
boolean |
|
Time unit for initialDelay and delay options. Enum values:
|
MILLISECONDS |
TimeUnit |
|
Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details. |
true |
boolean |
Producer behavior is affected by the command
parameter which tells
what to do with the job, it can be
The consumer may delete the job immediately after reserving it or wait
until Camel routes process it. While the first scenario is more like a
“message queue”, the second is similar to “job queue”. This behavior is
controlled by awaitJob
parameter, which equals true
by
default (following Beanstalkd nature).
When synchronous, the consumer calls delete
on successful job
completion and calls bury
on failure. You can choose which command to
execute in the case of failure by
specifying onFailure
parameter in the URI. It can take values
of bury
, delete
or release
.
There is a boolean parameter useBlockIO
which corresponds to
the same parameter in JavaBeanstalkClient library. By default it
is true
.
Be careful when specifying release
, as the failed job will immediately
become available in the same tube and your consumer will try to acquire
it again. You can release
and specify jobDelay though.
The beanstalk consumer is a Scheduled Polling Consumer which means there is more options you can configure, such as how frequent the consumer should poll. For more details see Polling Consumer.
Consumer Headers
The consumer stores a number of job headers in the Exchange message:
Property | Type | Description |
---|---|---|
beanstalk.jobId |
long |
Job ID |
beanstalk.tube |
string |
the name of the tube that contains this job |
beanstalk.state |
string |
“ready” or “delayed” or “reserved” or “buried” (must be “reserved”) |
beanstalk.priority |
long |
the priority value set |
beanstalk.age |
int |
the time in seconds since the put command that created this job |
beanstalk.time-left |
int |
the number of seconds left until the server puts this job into the ready queue |
beanstalk.timeouts |
int |
the number of times this job has timed out during a reservation |
beanstalk.releases |
int |
the number of times a client has released this job from a reservation |
beanstalk.buries |
int |
the number of times this job has been buried |
beanstalk.kicks |
int |
the number of times this job has been kicked |
Examples
This Camel component lets you both request the jobs for processing and supply them to Beanstalkd daemon. Our simple demo routes may look like
from("beanstalk:testTube").
log("Processing job #${exchangeProperty.beanstalk.jobId} with body ${in.body}").
process(new Processor() {
@Override
public void process(Exchange exchange) {
// try to make integer value out of body
exchange.getIn().setBody( Integer.valueOf(exchange.getIn().getBody(classOf[String])) );
}
}).
log("Parsed job #${exchangeProperty.beanstalk.jobId} to body ${in.body}");
from("timer:dig?period=30seconds").
setBody(constant(10)).log("Kick ${in.body} buried/delayed tasks").
to("beanstalk:testTube?command=kick");
In the first route we are listening for new jobs in tube “testTube”. When they are arriving, we are trying to parse integer value from the message body. If done successful, we log it and this successful exchange completion makes Camel component to delete this job from Beanstalk automatically. Contrary, when we cannot parse the job data, the exchange failed and the Camel component buries it by default, so that it can be processed later or probably we are going to inspect failed jobs manually.
So the second route periodically requests Beanstalk to kick 10 jobs out of buried and/or delayed state to the normal queue.
Spring Boot Auto-Configuration
When using beanstalk 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-beanstalk-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
The component supports 5 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
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 |
|
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 |
|
Custom ConnectionSettingsFactory. Specify which ConnectionSettingsFactory to use to make connections to Beanstalkd. Especially useful for unit testing without beanstalkd daemon (you can mock ConnectionSettings). The option is a org.apache.camel.component.beanstalk.ConnectionSettingsFactory type. |
ConnectionSettingsFactory |
||
Whether to enable auto configuration of the beanstalk component. This is enabled by default. |
Boolean |
||
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 |