ListFile
Description
Retrieves a listing of files from the input directory. For each file listed, creates a FlowFile that represents the file so that it can be fetched in conjunction with FetchFile. This Processor is designed to run on Primary Node only in a cluster when 'Input Directory Location' is set to 'Remote'. If the primary node changes, the new Primary Node will pick up where the previous node left off without duplicating all the data. When 'Input Directory Location' is 'Local', the 'Execution' mode can be anything, and synchronization won't happen. Unlike GetFile, this Processor does not delete any data from the local filesystem.
Tags
file, filesystem, get, ingest, list, source
Properties
In the list below required Properties are shown with an asterisk (*). Other properties are considered optional. The table also indicates any default values, and whether a property supports the NiFi Expression Language.
| Display Name | API Name | Default Value | Allowable Values | Description |
|---|---|---|---|---|
| Input Directory * | Input Directory | The input directory from which files to pull files Supports Expression Language, using Environment variables. | ||
| Listing Strategy * | listing-strategy | Tracking Timestamps |
| Specify how to determine new/updated entities. See each strategy descriptions for detail. |
| Recurse Subdirectories * | Recurse Subdirectories | true |
| Indicates whether to list files from subdirectories of the directory |
| Record Writer | record-writer | Controller Service: RecordSetWriterFactory Implementations: AvroRecordSetWriter CSVRecordSetWriter FreeFormTextRecordSetWriter JsonRecordSetWriter RecordSetWriterLookup ScriptedRecordSetWriter XMLRecordSetWriter | Specifies the Record Writer to use for creating the listing. If not specified, one FlowFile will be created for each entity that is listed. If the Record Writer is specified, all entities will be written to a single FlowFile instead of adding attributes to individual FlowFiles. | |
| Input Directory Location * | Input Directory Location | Local |
| Specifies where the Input Directory is located. This is used to determine whether state should be stored locally or across the cluster. |
| File Filter * | File Filter | [^.].* | Only files whose names match the given regular expression will be picked up | |
| Path Filter | Path Filter | When Recurse Subdirectories is true, then only subdirectories whose path matches the given regular expression will be scanned | ||
| Include File Attributes * | Include File Attributes | true |
| Whether or not to include information such as the file's Last Modified Time and Owner as FlowFile Attributes. Depending on the File System being used, gathering this information can be expensive and as a result should be disabled. This is especially true of remote file shares. |
| Minimum File Age * | Minimum File Age | 0 sec | The minimum age that a file must be in order to be pulled; any file younger than this amount of time (according to last modification date) will be ignored | |
| Maximum File Age | Maximum File Age | The maximum age that a file must be in order to be pulled; any file older than this amount of time (according to last modification date) will be ignored | ||
| Minimum File Size * | Minimum File Size | 0 B | The minimum size that a file must be in order to be pulled | |
| Maximum File Size | Maximum File Size | The maximum size that a file can be in order to be pulled | ||
| Ignore Hidden Files * | Ignore Hidden Files | true |
| Indicates whether or not hidden files should be ignored |
| Target System Timestamp Precision * | target-system-timestamp-precision | Auto Detect |
| Specify timestamp precision at the target system. Since this processor uses timestamp of entities to decide which should be listed, it is crucial to use the right timestamp precision. |
| Entity Tracking State Cache | et-state-cache | Controller Service: DistributedMapCacheClient Implementations: HazelcastMapCacheClient MapCacheClientService RedisDistributedMapCacheClientService SimpleRedisDistributedMapCacheClientService | Listed entities are stored in the specified cache storage so that this processor can resume listing across NiFi restart or in case of primary node change. 'Tracking Entities' strategy require tracking information of all listed entities within the last 'Tracking Time Window'. To support large number of entities, the strategy uses DistributedMapCache instead of managed state. Cache key format is 'ListedEntities::{processorId}(::{nodeId})'. If it tracks per node listed entities, then the optional '::{nodeId}' part is added to manage state separately. E.g. cluster wide cache key = 'ListedEntities::8dda2321-0164-1000-50fa-3042fe7d6a7b', per node cache key = 'ListedEntities::8dda2321-0164-1000-50fa-3042fe7d6a7b::nifi-node3' The stored cache content is Gzipped JSON string. The cache key will be deleted when target listing configuration is changed. Used by 'Tracking Entities' strategy. | |
| Entity Tracking Time Window | et-time-window | 3 hours | Specify how long this processor should track already-listed entities. 'Tracking Entities' strategy can pick any entity whose timestamp is inside the specified time window. For example, if set to '30 minutes', any entity having timestamp in recent 30 minutes will be the listing target when this processor runs. A listed entity is considered 'new/updated' and a FlowFile is emitted if one of following condition meets: 1. does not exist in the already-listed entities, 2. has newer timestamp than the cached entity, 3. has different size than the cached entity. If a cached entity's timestamp becomes older than specified time window, that entity will be removed from the cached already-listed entities. Used by 'Tracking Entities' strategy. Supports Expression Language, using Environment variables. | |
| Entity Tracking Initial Listing Target | et-initial-listing-target | All Available |
| Specify how initial listing should be handled. Used by 'Tracking Entities' strategy. |
| Entity Tracking Node Identifier | et-node-identifier | ${hostname()} | The configured value will be appended to the cache key so that listing state can be tracked per NiFi node rather than cluster wide when tracking state is scoped to LOCAL. Used by 'Tracking Entities' strategy. Supports Expression Language, using Environment variables. | |
| Track Performance * | track-performance | false |
| Whether or not the Processor should track the performance of disk access operations. If true, all accesses to disk will be recorded, including the file being accessed, the information being obtained, and how long it takes. This is then logged periodically at a DEBUG level. While the amount of data will be capped, this option may still consume a significant amount of heap (controlled by the 'Maximum Number of Files to Track' property), but it can be very useful for troubleshooting purposes if performance is poor is degraded. |
| Maximum Number of Files to Track * | max-performance-metrics | 100000 | If the 'Track Performance' property is set to 'true', this property indicates the maximum number of files whose performance metrics should be held onto. A smaller value for this property will result in less heap utilization, while a larger value may provide more accurate insights into how the disk access operations are performing Supports Expression Language, using Environment variables. | |
| Max Disk Operation Time | max-operation-time | 10 secs | The maximum amount of time that any single disk operation is expected to take. If any disk operation takes longer than this amount of time, a warning bulletin will be generated for each operation that exceeds this amount of time. Supports Expression Language, using Environment variables. | |
| Max Directory Listing Time | max-listing-time | 3 mins | The maximum amount of time that listing any single directory is expected to take. If the listing for the directory specified by the 'Input Directory' property, or the listing of any subdirectory (if 'Recurse' is set to true) takes longer than this amount of time, a warning bulletin will be generated for each directory listing that exceeds this amount of time. Supports Expression Language, using Environment variables. |
Dynamic Properties
This component does not support dynamic properties.
Relationships
| Name | Description |
|---|---|
| success | All FlowFiles that are received are routed to success |
Reads Attributes
This processor does not read attributes.
Writes Attributes
| Name | Description |
|---|---|
| absolute.path | The absolute.path is set to the absolute path of the file's directory on filesystem. For example, if the Input Directory property is set to /tmp, then files picked up from /tmp will have the path attribute set to "/tmp/". If the Recurse Subdirectories property is set to true and a file is picked up from /tmp/abc/1/2/3, then the path attribute will be set to "/tmp/abc/1/2/3/". |
| file.creationTime | The timestamp of when the file in filesystem was created as 'yyyy-MM-dd'T'HH:mm:ssZ' |
| file.group | The group that owns the file in filesystem |
| file.lastAccessTime | The timestamp of when the file in filesystem was last accessed as 'yyyy-MM-dd'T'HH:mm:ssZ' |
| file.lastModifiedTime | The timestamp of when the file in filesystem was last modified as 'yyyy-MM-dd'T'HH:mm:ssZ' |
| file.owner | The user that owns the file in filesystem |
| file.permissions | The permissions for the file in filesystem. This is formatted as 3 characters for the owner, 3 for the group, and 3 for other users. For example rw-rw-r-- |
| file.size | The number of bytes in the file in filesystem |
| filename | The name of the file that was read from filesystem. |
| path | The path is set to the relative path of the file's directory on filesystem compared to the Input Directory property. For example, if Input Directory is set to /tmp, then files picked up from /tmp will have the path attribute set to "/". If the Recurse Subdirectories property is set to true and a file is picked up from /tmp/abc/1/2/3, then the path attribute will be set to "abc/1/2/3/". |
State Management
| Scope | Description |
|---|---|
| CLUSTER, LOCAL | After performing a listing of files, the timestamp of the newest file is stored. This allows the Processor to list only files that have been added or modified after this date the next time that the Processor is run. Whether the state is stored with a Local or Cluster scope depends on the value of the <Input Directory Location> property. |
Restricted
This component is not restricted.
Input Requirement
This component does not allow an incoming relationship.
System Resource Considerations
This component does not specify system resource considerations.