supplement /bin stores commands that can be operated in single user mode
/Software / command / script that will not be used when usr/sbin Linux system starts up
/Under usr/bin are all executable programs pre installed by the system, and the system upgrade may be overwritten
/The usr/local/bin directory is where users can place their own executable programs

/fdfs file under usr/bin /

fdfs_append_file
fdfs_appender_test
fdfs_appender_test1
fdfs_crc32
fdfs_delete_file
fdfs_download_file
fdfs_file_info
fdfs_monitor
fdfs_storaged
fdfs_test fdfs_test1
fdfs_trackerd
fdfs_upload_appender
fdfs_upload_file

1,fdfs_upload_file Use "fdfs_upload_file" to indicate the file to be uploaded. The command is:

method: fdfs_upload_file <config_file> <local_filename>
For example:/usr/bin/fdfs_upload_file /etc/fdfs/client.conf a.txt

Upload process FastDFS provides users with basic file access interfaces, such as upload, download, append, delete, etc., which are provided to users in the form of client library. The Storage Server will periodically send its own storage information to the Tracker Server. When there is more than one Tracker Server in the Tracker Server Cluster, the relationship between each Tracker is equal, so the client can select any Tracker when uploading. When the Tracker receives the request from the client to upload a file, it will assign a group that can store the file to the file. When the group is selected, it is necessary to decide which storage server in the group is assigned to the client. After the storage server is allocated, the client sends a file write request to storage, and storage will allocate a data storage directory for the file. Then assign a fileid to the file, and finally generate a file name to store the file according to the above information. (1) Select tracker server
When there is more than one tracker server in the cluster, because the relationship between trackers is completely equal, the client can choose any trackcer when upload ing files. (2) Select storage group
When the tracker receives the request to upload a file, it will assign a group to the file that can store the file. The following rules for selecting a group are supported: 1 Round robin, polling between all groups 2 Specified group: specify a certain group 3 Load balance, more remaining storage space is preferred (3) Select storage server
When a group is selected, the tracker will select a storage server in the group for the client. The following rules for selecting storage are supported: 1 Round robin, poll 2.0% of all storage in the group First server ordered by ip, sorted by ip 3 First server ordered by priority (priority is configured on storage) (4) Select storage path
After the storage server is allocated, the client will send a file write request to storage, and storage will allocate a data storage directory for the file. The following rules are supported: 1 Round robin, polling among multiple storage directories 2 The one with the most remaining storage space is preferred (5) Generate Fileid
After selecting the storage directory, storage will generate a Fileid for the file, which is generated by storage server ip, file creation time, file size, file crc32 and a random number are spliced, and then the binary string is base64 encoded and converted into a printable string. (6) Select two-level directory
After selecting the storage directory, storage will assign a fileid to the file. There are two levels of 256 * 256 subdirectories under each storage directory. Storage will hash (guess) twice according to the file fileid, route to one of the subdirectories, and then store the file in the subdirectory with fileid as the file name. (7) Generate file name
When the file is stored in a subdirectory, it is considered that the file is successfully stored. Next, a file name will be generated for the file. The file name is spliced by group, storage directory, two-level subdirectory, fileid and file suffix (specified by the client and mainly used to distinguish file types). 2,fdfs_download_file Use "fdfs_download_file" to download files. The command is:

method: fdfs_download_file <config_file> <path>
For example:/usr/bin/fdfs_download_file /etc/fdfs/client.conf group1/M00/00/21/rBABl2IgEJ2AXTIxAAC5ERGBk_A734.png

Download process After the client uploadfile succeeds, it will get a file name generated by storage, and then the client can access the file according to this file name. [client can directly enter the storage to read and download. IP address / P port number / volume name / file name is required. If you only know the volume name and file name, go to the tracker. The tracker will find the storage node where the corresponding volume name and file name are located and return the ip/p to the user...] Like the upload file, the client can select any tracker server when downloading a file. When a tracker sends a download request to a tracker, it must bring the file name information. From the file name, track parses the group, size, creation time and other information of the file, and then selects a storage for the request to serve the read request. When a tracker sends a download request to a tracker, it must bring the file name information. From the file name, track parses the group, size, creation time and other information of the file, and then selects a storage for the request to serve the read request. Because the files in the group are synchronized asynchronously in the background, it is possible that the files have not been synchronized to some storage server s when they are read. In order to avoid accessing such storage as much as possible, the tracker selects the readable storage in the group according to the following rules. 1. The source storage to which the file is uploaded - as long as the source storage is alive, it must contain this file, and the address of the source is encoded in the file name. 2. File creation timestamp = = the timestamp to which the storage is synchronized, and (current time - file creation timestamp) > the maximum time of file synchronization (e.g. 5 minutes) - after the file is created, it is considered that after the maximum synchronization time, it must have been synchronized to other storage. 3. File creation timestamp < timestamp to which storage is synchronized- The file before the synchronization timestamp determines that it has been synchronized. 4. (current time - file creation timestamp) > synchronization delay threshold (such as one day)- After the synchronization delay threshold time, it is considered that the file must have been synchronized. 3,fdfs_file_info Using fdfs_file_info can view the detailed storage information of the file At this time, FastDFS will return the storage server node id of the file, the ip address of the storage server, the file upload time, the file size and the verification information of crc32 (to ensure the correctness of the data, we have to use the means of error detection).
Command:

method: fdfs_file_info <config_file> <path>
For example: /usr/bin/fdfs_file_info /etc/fdfs/client.conf group1/M00/00/1F/rBABtGIfljmACwDjAAC5ERGBk_A347.png  

4,fdfs_delete_file Using fdfs_delete_file to delete a file, command:

method: fdfs_delete_file <config_file> <path>
For example: /usr/bin/fdfs_delete_file /etc/fdfs/client.conf group1/M00/00/1F/rBABtGIfljmACwDjAAC5ERGBk_A347.png  

5, fdfs_upload_appender/fdfs_append_file Use "fdfs_upload_appender" to upload a file that can be appended, followed by the configuration file of the client and the path of the file to be uploaded:

# echo "upload_appende 2022-3-3"  >a.txt
# echo "upload_appender2 2022-3-3" >b.txt
#/usr/bin/fdfs_upload_appender /etc/fdfs/client.conf a.txt 
# cat rBABl2IgHTaENYMrAAAAADBEg7A330.txt 
upload_appender 2022-3-3

// Additional content
# /usr/bin/fdfs_append_file /etc/fdfs/client.conf group1/M09/00/21/rBABl2IgHTaENYMrAAAAADBEg7A330.txt b.txt 
# cat rBABl2IgHTaENYMrAAAAADBEg7A330.txt 
upload_appender 2022-3-3
upload_appender2 2022-3-3

Steps: First, the first file is uploaded to the storage server as an appendable file. Then use "fdfs_append_file" to indicate that the content can be appended to the end of the target file, followed by the client's configuration file, the path of the target file to be appended to the storage server, and the local file path of the content to be appended After observing the storage server, it is found that the file is still one, but the file content is successfully appended 6,fdfs_monitor to check whether the storage is automatically registered in the tracker Run in storage container or tracker container fdfs_monitor /etc/fdfs/storage.conf

//Delete storage node
usr/bin/fdfs_monitor /etc/fdfs/storage.conf delete group3 172.16.1.180 
//Add Storage nodes (automatically join through configuration).

//Status of the node
# FDFS_STORAGE_STATUS: INIT: initialization. The source server that has not been synchronized with the existing data
# FDFS_STORAGE_STATUS: WAIT_SYNC: wait for synchronization and get the source server that has synchronized the existing data
# FDFS_STORAGE_STATUS: synchronizing
# FDFS_STORAGE_STATUS: DELETED: DELETED. The server is removed from this group
# FDFS_STORAGE_STATUS: OFFLINE
# FDFS_STORAGE_STATUS: ONLINE: ONLINE, unable to provide service
# FDFS_STORAGE_STATUS: ACTIVE: online, can provide services

 # group_name: group name
 # ip_addr: IP address
 # version:
 # sync_src_ip_addr: the source server that synchronizes the existing data files to the storage server
 # sync_until_timestamp: deadline for synchronizing existing data files (UNIX timestamp)
 # Total storage: total storage
 # free storage
 # Upload priority: upload priority
 # store_path_count: number of paths
 # subdir_count_per_path: number of folders per level
 # storage_port
 # storage_http_port
 # current_write_path: current write path
 # Source storage id: source storage id 
 # if_trunk_server: whether to use trunk
 # connection.alloc_count
 # connection.current_count
 # connection.max_count: maximum number of concurrent connections
 # total_upload_count: number of file uploads
 # success_upload_count: number of successful file uploads
 # total_append_count: number of times to append files
 # success_append_count: the number of times the file was successfully appended
 # total_modify_count: total modification times
 # success_modify_count: number of successfully modified
 # total_truncate_count: total truncation count times
 # success_truncate_count: number of successful truncations
 # total_set_meta_count: number of times to change meta data
 # success_set_meta_count: the number of successful changes to meta data
 # total_delete_count: number of times to delete files
 # success_delete_count: the number of times the file was successfully deleted
 # total_download_count: number of file downloads
 # success_download_count: number of successful file downloads
 # total_get_meta_count: number of times to obtain meta data
 # success_get_meta_count: the number of times meta data was successfully obtained
 # total_create_link_count: number of links created
 # success_create_link_count: number of successful Link Creation
 # total_delete_link_count: number of deleted links
 # success_delete_link_count: number of successfully deleted links
 # total_upload_bytes: total number of uploaded bytes
 # success_upload_bytes: the total number of bytes uploaded successfully
 # total_append_bytes: append
 # success_append_bytes
 # total_modify_bytes 
 # success_modify_bytes
 # stotal_download_bytes
 # success_download_bytes
 # total_sync_in_bytes: synchronous bytes 
 # success_sync_in_bytes 
 # total_sync_out_bytes 
 # success_sync_out_bytes 
 # total_file_open_count 
 # success_file_open_count 
 # total_file_read_count 
 # success_file_read_count 
 # total_file_write_count: number of file writes
 # success_file_write_count: the number of files successfully written
 # last_heart_beat_time: the last time the storage sent a heartbeat to the tracker
 # last_source_update: the latest source update time (the update operation comes from the client)
 # last_sync_update: the latest synchronization update time (the update operation is from the synchronization of other storage server s)
 # last_synced_timestamp: timestamp of last synchronization 

7. Start command

service fdfs_storaged restart
service fdfs_trackerd  restart

docker Container startup service:
fdfs_storaged /etc/fdfs/storage.conf start
fdfs_trackerd /etc/fdfs/tracker.conf start

/usr/local/nginx/sbin/nginx -s reload
curl -i 127.0.0.1:8888 //View nginx version