Configure Photon Running Environment

The Designer Cloud® application can connect to a high-performance environment embedded in the Alteryx node for execution of jobs against small- to medium-sized datasets. This environment, called the Photon running environment, also supports working with much larger samples in the Transformer page, which enables you to build your recipes against dataset snapshots of higher fidelity. 

By default, the Photon running environment is enabled for new installations. Additional configuration is required.

Features:

• Faster execution times for transform and profiling jobs

• Larger sample sizes (up to 10MB by default). 

  NOTE: Since Photon supports larger sample sizes, some interactions may be slightly impacted. Loading states have been introduced to enable faster responsiveness from the application.

  Tip: For datasets that are smaller than the sample size limit, the Transformer Page displays the entire dataset in its transformed state. So, you can download the dataset from the Recipe Panel in Transformer Page without having to execute it on a remote server. This expanded capability allows for faster and more immediate local use of the product. See Recipe Panel.

• Better consistency with typecasting done in Hadoop jobs

This section provides information on how to enable and configure the Photon running environment. 

Known Limitations and Issues

Desktop Requirements

Example Configuration

The following are the default values for Photon enablement:

"photon": {
  "cacheEnabled": true,
  "numThreads": 4,
  "enabled": true,
  "distroPath": "/photon/dist/centos6/photon",
  "loadScalingFactor": 20,
  "traceExecution": false,
  "websocket": {
    "host": "localhost",
    "port": 8082
  },
  "mode": "pnacl"
},

  "distroPath": "/photon/dist/centos6/photon",

Recommended Photon Configuration by Core Count

On the Alteryx node, you can make adjustments to the resources claimed by the Photon running environment based on the number of cores on the machine. The following table identifies the recommended settings for a node with 8, 16, or 32 cores. The default settings assume 16 cores.

The number of simultaneous users is a competing factor.

• For a high number, more resources should be reserved for the webapp and the VFS services.
• For a low number, more resources for Photon should improve performance for sampling and job execution on the Photon running environment.

The following table illustrates some adjustments for a 16-core system:

Disable

This running environment is enabled by default. Please complete the following configuration to disable the running environment.

Steps:

1. You can apply this change through the Admin Settings Page (recommended) or trifacta-conf.json. For more information, see Platform Configuration Methods.

2. To disable the Alteryx Server, apply the following configuration settings:

   "webapp.runInTrifactaServer": false,
   "feature.enableSamplingScanOptions": false,
   "feature.enableFirstRowsSample": false, 

3. Do not change the following, which applies to the Photon web-client:

   "photon.enabled": true,

4. Save your changes and restart the platform.

Change Limits

Sample Size Limits

Increasing the sample size may degrade the user experience in the Transformer page in the following ways:

• Generation of column details and data grid histograms
• Preview card loading time

• Time required to complete brushing and linking in histograms

  NOTE: If you increase the sample size above the default setting and encounter unacceptable performance in the above areas, you should reduce the sample size settings.

When samples are created using the Photon running environment, their maximum size is determined by multiplying the values for the following settings. Default value is 10 MB.

Maximum Data in the Client

The following settings determine the maximum amount of data that is permitted to be passed to the client from Photon:

Timeouts

Photon runtime job timeout

By default, the Designer Cloud Powered by Trifacta platform imposes no limit on execution of a Photon job. As needed, you can enable and configure a limit. 

Steps:

1. You can apply this change through the Admin Settings Page (recommended) or trifacta-conf.json. For more information, see Platform Configuration Methods.

   "photon.timeoutEnabled": false,
   "photon.timeoutMinutes": 180,

   Setting	Description
   timeoutEnabled	Set to false to disable job limiting. Set to true to enable the timeout specified below.
   timeoutMinutes	Defines the number of minutes that a Photon job is permitted to run. Default value is 180 (three hours).

2. Save your changes and restart the platform.

When a job has failed due to exceeding a timeout, additional information is available in the job logs. The following is a good search term for this type of error:

java.lang.Exception: Photon job '<jobId>' timeout

where <jobId> is the internal job identifier.

Job logs can be downloaded from the Job page. See Jobs Page.

Photon memory timeout

To prevent crashes of the server, Photon imposes a memory consumption limit for each job. If this memory timeout is exceeded, the job is automatically killed. As needed, you can disable this memory protection (not recommended) or change the memory threshold when jobs are killed.  

Steps:

1. You can apply this change through the Admin Settings Page (recommended) or trifacta-conf.json. For more information, see Platform Configuration Methods.

2. Locate the following settings:

   "photon.memoryMonitorEnabled": false,
   "photon.memoryPercentageThresold": 60,

   Setting	Description
   memoryMonitorEnabled	Set to false to disable memory monitoring. Set to true to enable the threshold specified below.
   memoryPercentageThreshold	Defines the percentage of total available system memory that a Photon job process is permitted to consume. Default value is 60 (60%). Tip: This threshold applies to individual Photon jobs. If this threshold value is over 50%, it is possible for two concurrent Photon jobs to use more than the available memory, crash the server, and force a restart. You may wish to start by setting threshold values at a lower level.

3. Save your changes and restart the platform.

When a job has failed due to exceeding this memory threshold, additional information is available in the job logs. The following is a good search term for this type of error:

java.lang.Exception: Photon job '<jobId>' failed with memory consumption over threshold

where <jobId> is the internal job identifier.

Below this line item, you may see the following entries, which can provide additional information to adjust the memory settings:

2017-05-04T02:26:40.549Z [job-id 740] com.trifacta.joblaunch.util.ProcessMonitorUtil [Thread-20] INFO  com.trifacta.joblaunch.util.ProcessMonitorUtil - Global memory size: 8373186560 bytes
2017-05-04T02:26:40.555Z [job-id 740] com.trifacta.joblaunch.util.ProcessMonitorUtil [Thread-20] INFO  com.trifacta.joblaunch.util.ProcessMonitorUtil - Available global memory size at process start: 2672959488 bytes
...
2017-05-04T02:29:15.690Z [job-id 740] com.trifacta.joblaunch.util.ProcessMonitorUtil [Thread-20] INFO  com.trifacta.joblaunch.util.ProcessMonitorUtil - Current memory consumption: 5.614080429077148%
2017-05-04T02:29:15.691Z [job-id 740] com.trifacta.joblaunch.util.ProcessMonitorUtil [Thread-20] ERROR com.trifacta.joblaunch.util.ProcessMonitorUtil - Average memory consumption for the past 15 seconds over 5% threshold: 5.174326801300049 %. Current available global memory: 2244628480 bytes

Current memory consumption

Job logs can be downloaded from the Job page. See Jobs Page.

Batch FileSystem Access Timeout Settings

The default timeout settings for reading and writing of data from the client browser through Photon should work in most cases. 

Particularly when reading from large tables, you might discover errors similar to the following:

06:21:21.365 [Job 23] INFO com.trifacta.hadoopdata.photon.BatchPhotonRunner - terminating with uncaught exception of type Poco::TimeoutException: Timeout
06:21:21.375 [Job 23] INFO com.trifacta.hadoopdata.photon.BatchPhotonRunner - /vagrant/photon/dist/centos6/photon/bin/photon-cli: line 22: 15639 Aborted $
Unknown macro: {command[@]}

Steps:

1. You can apply this change through the Admin Settings Page (recommended) or trifacta-conf.json. For more information, see Platform Configuration Methods.

2. Locate the photon.extraCliArgs node.

3. Add the following values to the extraCliArgs entry:

   "photon.extraCliArgs" : "-batch_vfs_read_timeout <300> -batch_vfs_write_timeout <300>"

   Argument	Description
   -batch_vfs_read_timeout	Timeout limit in seconds of read operations from the datastore. Default value is 300 seconds (5 minutes). Tip: Raising the value to 3600 seconds should be fine in most environments. Avoid setting this value above 7200 seconds (2 hours).
   -batch_vfs_write_timeout	Timeout limit in seconds of write operations to the datastore. Default value is 300 seconds (5 minutes). NOTE: Do not modify unless specifically instructed by Alteryx Support.

4. To reduce timeouts, raise the above settings.
5. Save your changes and restart the platform. 

Configure VFS Service

The VFS Service serves the front-end interface and brokers connections with the backend datastores when the Photon running environment is enabled.

Steps:

1. You can apply this change through the Admin Settings Page (recommended) or trifacta-conf.json. For more information, see Platform Configuration Methods.

2. Locate the following configuration: 

   "vfs-service.port":41913,
   "vfs-service.loggerOptions.silent":false,
   "vfs-service.loggerOptions.level":"info",
   "vfs-service.loggerOptions.json":false,
   "vfs-service.loggerOptions.format":":method :url :status :res[content-length] :response-time :referrer :remote-addr :trifacta-user :user-agent",
   "vfs-service.host":"localhost",
   "vfs-service.enabled":true,
   "vfs-service.bindHost":"0.0.0.0",
   "vfs-service.autoRestart":true,

3. Verify that the enabled parameter is set to true.
4. Additional configuration settings are described below. 
5. Save your changes and restart the platform.

Use Photon

When Photon is enabled, it is available like any other running environment in the application. When executing a job, select the Run on Alteryx Server option from the drop-down in the Run Job dialog.