Blob

Scenarios

The Blob server on the JobManager node is used to receive JAR files uploaded by users on the client, send JAR files to TaskManager, and transfer log files. Flink provides some items for configuring the Blob server. You can configure them in the flink-conf.yaml configuration file.

Configuration Description

Users can configure the port, SSL, retry times, and concurrency.

**Table 1** Parameters
Parameter	Description	Default Value	Mandatory
blob.server.port	Blob server port	32456 to 32520	No
blob.service.ssl.enabled	Indicates whether to enable the encryption for the blob transmission channel. This parameter is valid only when the global switch security.ssl is enabled.	true	Yes
blob.fetch.retries	Number of times that TaskManager tries to download blob files from JobManager.	50	No
blob.fetch.num-concurrent	Number of concurrent tasks for downloading blob files supported by JobManager.	50	No
blob.fetch.backlog	Number of blob files, such as .jar files, to be downloaded in the queue supported by JobManager. The unit is count.	1000	No
library-cache-manager.cleanup.interval	Interval at which JobManager deletes the JAR files stored on the HDFS when the user cancels the Flink job. The unit is second.	3600	No