{ "slug": "Nats-Jet-Strem--Hello-World-d909099c88e4", "title": "Nats Jet Strem, Hello World", "subtitle": "Run simple Nats Jet Stream example", "excerpt": "Run simple Nats Jet Stream example", "date": "2022-12-28", "tags": [ "NATS" ], "readingTime": "6 min", "url": "https://medium.com/@mobinshaterian/nats-jet-strem-hello-world-d909099c88e4", "hero": "https://cdn-images-1.medium.com/max/800/1*H3kuWrFW58SPbqbe14pltw.png", "content": [ { "type": "heading", "level": 2, "text": "Nats Jet Strem, Hello World" }, { "type": "embed", "provider": "youtube", "url": "https://www.youtube.com/embed/hjXIUPZ7ArM?list=PLgqCaaYodvKY22TpvwlsalIArTmc56W9h" }, { "type": "paragraph", "html": "Download and install from the release form this web site." }, { "type": "code", "lang": "bash", "code": "go get github.com/nats-io/nats-server/v2" }, { "type": "paragraph", "html": "for install Nats-cli follow below link:" }, { "type": "code", "lang": "text", "code": "https://github.com/nats-io/natscli" }, { "type": "heading", "level": 2, "text": "Run Nats server" }, { "type": "code", "lang": "bash", "code": "nats server run" }, { "type": "code", "lang": "text", "code": "[54726] [INF] Starting nats-server[54726] [INF] Version: 2.9.6[54726] [INF] Git: [not\nset][54726] [INF] Name: nats_development[54726] [INF] ID:\nNCT7AV2WQ5UUD3EXWS3WJ6RBFP5GRQQ7D6UWK345VGXDQ24PQI3PPN4O[54726] [INF] Using configuration file:\n/tmp/nats-server-run-1900677043.cfg[54726] [INF] Listening for client connections on\n0.0.0.0:36275[54726] [INF] Server is ready" }, { "type": "heading", "level": 2, "text": "Select the Context" }, { "type": "code", "lang": "bash", "code": "nats context select nats_development" }, { "type": "code", "lang": "text", "code": "NATS Configuration Context \"nats_development\" Description: Local user access for NATS\nDevelopment instance Server URLs: nats://0.0.0.0:36275 Username: local\nPassword: ********* Path: /home/usr/.config/nats/context/nats_development.json" }, { "type": "heading", "level": 2, "text": "Mechanism Request Reply" }, { "type": "heading", "level": 3, "text": "Reply data from the topic" }, { "type": "code", "lang": "bash", "code": "nats reply hello.jermy \"hi\"" }, { "type": "code", "lang": "text", "code": "11:16:55 Listening on \"hello.jermy\" in group \"NATS-RPLY-22\"11:22:33 [#0] Received on subject\n\"hello.jermy\":11:22:36 [#1] Received on subject \"hello.jermy\":11:22:41 [#2] Received on subject\n\"hello.jermy\":11:22:44 [#3] Received on subject \"hello.jermy\":" }, { "type": "heading", "level": 3, "text": "Request Data into the topic" }, { "type": "code", "lang": "bash", "code": "nats req hello.jermy \"\"" }, { "type": "code", "lang": "text", "code": "11:22:44 Sending request on \"hello.jermy\"11:22:44 Received with rtt 403.218µshi" }, { "type": "code", "lang": "bash", "code": "nats req hello.jermy \"{ \"hi\" : \"bye\" }\"11:26:33 Sending request on \"hello.jermy\"11:26:33 Received\nwith rtt 399.847µshi" }, { "type": "code", "lang": "text", "code": "Recive :11:26:33 [#6] Received on subject \"hello.jermy\":{ hi : bye }" }, { "type": "heading", "level": 2, "text": "Mechanism Pub Sub" }, { "type": "heading", "level": 3, "text": "sub receive data from the topic" }, { "type": "code", "lang": "bash", "code": "nats sub hello.world[#2] Received on \"hello.world\"hi?" }, { "type": "heading", "level": 3, "text": "Publish data to the topic" }, { "type": "code", "lang": "bash", "code": "nats pub hello.world \"hi?\"11:46:50 Published 3 bytes to \"hello.world\"" }, { "type": "heading", "level": 2, "text": "Mechanism many Pub and 1 Sub" }, { "type": "heading", "level": 3, "text": "sub receive data from the topic" }, { "type": "code", "lang": "bash", "code": "nats sub hello.world[#483] Received on \"hello.world\"hi, guys[#484] Received on \"hello.world\"group 2" }, { "type": "heading", "level": 3, "text": "Publish data to the topic" }, { "type": "code", "lang": "bash", "code": "nats pub hello.world \"hi, guys\" --count=-1 --sleep=1s" }, { "type": "code", "lang": "bash", "code": "nats pub hello.world \"group 2\" --count=-1 --sleep=1s" }, { "type": "heading", "level": 2, "text": "Mechanism 1 Pub and many Sub" }, { "type": "paragraph", "html": "Fan out Design pattern" }, { "type": "image", "src": "https://cdn-images-1.medium.com/max/800/1*H3kuWrFW58SPbqbe14pltw.png", "alt": "Nats Jet Strem, Hello World", "caption": "", "width": 987, "height": 574 }, { "type": "embed", "provider": "youtube", "url": "https://www.youtube.com/embed/8BEwZnUIZfw?feature=oembed" }, { "type": "image", "src": "https://cdn-images-1.medium.com/max/800/1*gU1K-YBBdBNivOYSCzHa4w.png", "alt": "Nats Jet Strem, Hello World", "caption": "", "width": 740, "height": 574 }, { "type": "paragraph", "html": "2 subs receive data from the topic" }, { "type": "code", "lang": "bash", "code": "nats sub hello.world04:32:15 Subscribing on hello.world [#1] Received on \"hello.world\"message" }, { "type": "code", "lang": "bash", "code": "nats sub hello.world04:33:03 Subscribing on hello.world [#1] Received on \"hello.world\"message" }, { "type": "paragraph", "html": "Publish data to the topic" }, { "type": "code", "lang": "bash", "code": "nats pub hello.world \"message\"04:33:20 Published 7 bytes to \"hello.world\"" }, { "type": "heading", "level": 2, "text": "Mechanism 1 Pub and many Sub with queue" }, { "type": "paragraph", "html": "In this Mechanim only one of the sub will get the data" }, { "type": "heading", "level": 3, "text": "2 subs receive data from the topic" }, { "type": "code", "lang": "bash", "code": "nats sub hello.world --queue greeter04:34:26 Subscribing on hello.world [#1] Received on\n\"hello.world\"message" }, { "type": "code", "lang": "bash", "code": "nats sub hello.world --queue greeter04:34:42 Subscribing on hello.world" }, { "type": "heading", "level": 3, "text": "Publish data to the topic" }, { "type": "code", "lang": "bash", "code": "nats pub hello.world \"message\"04:34:56 Published 7 bytes to \"hello.world\"" }, { "type": "paragraph", "html": "If sending 1000 messages in this method, we will get as unique distributed in all of each pub services." }, { "type": "code", "lang": "bash", "code": "nats pub hello.world \"message\" --count 10001000 / 1000\n[========================================================================================================================================] 0s" }, { "type": "code", "lang": "text", "code": "[#501] Received on \"hello.world\"message" }, { "type": "code", "lang": "text", "code": "[#499] Received on \"hello.world\"message[#500] Received on \"hello.world\"message" }, { "type": "heading", "level": 2, "text": "Nats JetsStream" }, { "type": "code", "lang": "bash", "code": "nats server run --jetstream" }, { "type": "paragraph", "html": "Context selected" }, { "type": "code", "lang": "bash", "code": "nats context select nats_developmentNATS Configuration Context \"nats_development\" Description:\nLocal user access for NATS Development instance Server URLs: nats://0.0.0.0:36275\nUsername: local Password: ********* Path:\n/home/user/.config/nats/context/nats_development.json" }, { "type": "paragraph", "html": "List of Nats Jetstream exist" }, { "type": "code", "lang": "bash", "code": "nats stream lsNo Streams defined" }, { "type": "paragraph", "html": "Watch Nats Stream lists" }, { "type": "code", "lang": "text", "code": "watch nats stream ls" }, { "type": "paragraph", "html": "Make Nats Stream" }, { "type": "code", "lang": "bash", "code": "nats stream add" }, { "type": "code", "lang": "text", "code": "? Stream Name orders? Subjects orders.*? Storage file? Replication 1? Retention Policy Limits?\nDiscard Policy Old? Stream Messages Limit -1? Per Subject Messages Limit -1? Total Stream Size -1?\nMessage TTL -1? Max Message Size -1? Duplicate tracking time window 2m0s? Allow message Roll-ups No?\nAllow message deletion Yes? Allow purging subjects or the entire stream YesStream orders was created" }, { "type": "image", "src": "https://cdn-images-1.medium.com/max/800/1*ZNmvyCkaPKSMK9Ce-sCC7A.png", "alt": "Nats Jet Strem, Hello World", "caption": "", "width": 733, "height": 202 }, { "type": "paragraph", "html": "send Message into orders" }, { "type": "code", "lang": "bash", "code": "nats pub orders.us \"{{.Count}}\" --count 1000010000 / 10000\n[========================================================================================================================================] 1s" }, { "type": "image", "src": "https://cdn-images-1.medium.com/max/800/1*Zsc_s-t_XpDDHeywDdcksw.png", "alt": "Nats Jet Strem, Hello World", "caption": "", "width": 738, "height": 206 }, { "type": "paragraph", "html": "Read from stream" }, { "type": "code", "lang": "bash", "code": "nats sub --stream orders" }, { "type": "code", "lang": "text", "code": "[#19999] Received JetStream message: stream: orders seq 19999 / subject: orders.eu / time:\n2022-12-28T05:03:48+03:309999[#20000] Received JetStream message: stream: orders seq 20000 /\nsubject: orders.eu / time: 2022-12-28T05:03:48+03:3010000[#20001] Received JetStream message:\nstream: orders seq 20001 / subject: orders.us / time: 2022-12-28T05:05:36+03:301[#21999] Received\nJetStream message: stream: orders seq 21999 / subject: orders.eu / time:\n2022-12-28T05:05:40+03:30999[#22000] Received JetStream message: stream: orders seq 22000 / subject:\norders.eu / time: 2022-12-28T05:05:40+03:301000" }, { "type": "paragraph", "html": "Reading all messages from the topics again" }, { "type": "code", "lang": "bash", "code": "nats sub --stream orders --all" }, { "type": "paragraph", "html": "Reading new messages from the topic" }, { "type": "code", "lang": "bash", "code": "nats sub --stream orders --new05:08:21 Subscribing to JetStream Stream holding messages with subject\norders.* delivering any new messages received" }, { "type": "paragraph", "html": "Reading only last message" }, { "type": "code", "lang": "bash", "code": "nats sub --stream orders --last" }, { "type": "code", "lang": "text", "code": "05:09:19 Subscribing to JetStream Stream holding messages with subject orders.* starting with the\nlast message received [#1] Received JetStream message: stream: orders seq 22000 / subject: orders.eu\n/ time: 2022-12-28T05:05:40+03:301000" }, { "type": "paragraph", "html": "Get last message from specific subject" }, { "type": "code", "lang": "bash", "code": "nats sub --stream orders --last-per-subject orders.us05:10:44 Subscribing to JetStream Stream\nholding messages with subject orders.us for the last messages for each subject in the Stream [#1]\nReceived JetStream message: stream: orders seq 21000 / subject: orders.us / time:\n2022-12-28T05:05:37+03:301000" }, { "type": "paragraph", "html": "Get messages from specific sequence" }, { "type": "code", "lang": "bash", "code": "nats sub --stream orders --start-sequence=21900" }, { "type": "paragraph", "html": "Reading messages and clean up the queue" }, { "type": "code", "lang": "bash", "code": "nats sub \"orders.*\" --durable my_consumer" }, { "type": "heading", "level": 2, "text": "Create Consumer" }, { "type": "code", "lang": "bash", "code": "nats consumer create? Consumer name pull_consumer? Delivery target (empty for Pull Consumers) ?\nStart policy (all, new, last, subject, 1h, msg sequence) all? Acknowledgement policy explicit?\nReplay policy instant? Filter Stream by subject (blank for all) ? Maximum Allowed Deliveries -1?\nMaximum Acknowledgements Pending 0? Deliver headers only without bodies No? Add a Retry Backoff\nPolicy No? Select a Stream ordersInformation for Consumer orders > pull_consumer created\n2022-12-28T05:22:57+03:30" }, { "type": "paragraph", "html": "Pull messages" }, { "type": "code", "lang": "bash", "code": "nats consumer next orders pull_consumer --count=10[05:24:09] subj: orders.us / tries: 1 / cons seq:\n1 / str seq: 1 / pending: 21,9991Acknowledged message[05:24:09] subj: orders.us / tries: 1 / cons\nseq: 2 / str seq: 2 / pending: 21,9982Acknowledged message[05:24:09] subj: orders.us / tries: 1 /\ncons seq: 3 / str seq: 3 / pending: 21,9973Acknowledged message[05:24:09] subj: orders.us / tries: 1\n/ cons seq: 4 / str seq: 4 / pending: 21,9964Acknowledged message[05:24:09] subj: orders.us / tries:\n1 / cons seq: 5 / str seq: 5 / pending: 21,9955Acknowledged message[05:24:09] subj: orders.us /\ntries: 1 / cons seq: 6 / str seq: 6 / pending: 21,9946Acknowledged message[05:24:09] subj: orders.us\n/ tries: 1 / cons seq: 7 / str seq: 7 / pending: 21,9937Acknowledged message[05:24:09] subj:\norders.us / tries: 1 / cons seq: 8 / str seq: 8 / pending: 21,9928Acknowledged message[05:24:09]\nsubj: orders.us / tries: 1 / cons seq: 9 / str seq: 9 / pending: 21,9919Acknowledged\nmessage[05:24:09] subj: orders.us / tries: 1 / cons seq: 10 / str seq: 10 / pending:\n21,99010Acknowledged message" }, { "type": "paragraph", "html": "Check consumer" }, { "type": "code", "lang": "bash", "code": "nats consumer info? Select a Stream orders? Select a Consumer pull_consumerInformation for Consumer\norders > pull_consumer created 2022-12-28T05:22:57+03:30Configuration: Durable Name:\npull_consumer Pull Mode: true Deliver Policy: All Ack Policy: Explicit\nAck Wait: 30s Replay Policy: Instant Max Ack Pending: 1,000 Max Waiting Pulls: 512State:\nLast Delivered Message: Consumer sequence: 10 Stream sequence: 10 Last delivery: 1m8s ago\nAcknowledgment floor: Consumer sequence: 10 Stream sequence: 10 Last Ack: 1m8s ago\nOutstanding Acks: 0 out of maximum 1,000 Redelivered Messages: 0 Unprocessed Messages:\n21,990 Waiting Pulls: 0 of maximum 512" }, { "type": "heading", "level": 2, "text": "Nats Key value store" }, { "type": "code", "lang": "bash", "code": "nats kverror: a subcommand from the list below is required, use --help for full help including flags\nand argumentsusage: nats kv [ ...]Interacts with a JetStream based Key-Value\nstoreThe JetStream Key-Value store uses streams to store key-value pairs for an indefinite period or\na per-bucket configured TTL.Subcommands: kv add Adds a new KV Store Bucket kv put Puts a\nvalue into a key kv get Gets a value for a key kv create Puts a value into a key only if\nthe key is new or\nit's last operation was a delete kv update Updates a key with a new value if the previous value matches the given revision kv del Deletes a key or the entire bucket kv purge Deletes a key from the bucket, clearing history before creating a delete marker kv history Shows the full history for a key kv revert Reverts a value to a previous revision using put kv info View the status of a KV store kv watch Watch the bucket or a specific key for updated kv ls List available buckets or the keys in a bucket kv compact Removes all historic values from the store where the last value is a delete" }, { "type": "paragraph", "html": "Create key value buket" }, { "type": "code", "lang": "bash", "code": "nats kv add oneInformation for Key-Value Store Bucket one created\n2022-12-28T05:30:54+03:30Configuration: Bucket Name: one History Kept: 1\nValues Stored: 0 Backing Store Kind: JetStream Bucket Size: 0 B Maximum Bucket Size:\nunlimited Maximum Value Size: unlimited JetStream Stream: KV_one Storage: File" }, { "type": "paragraph", "html": "Set key and value" }, { "type": "code", "lang": "bash", "code": "nats kv put one hello world" }, { "type": "code", "lang": "bash", "code": "nats kv watch one[2022-12-28 05:33:17] PUT one > hello: world" }, { "type": "image", "src": "https://cdn-images-1.medium.com/max/800/1*8viNJ3Ji2X8YLpgePl7D4Q.png", "alt": "Nats Jet Strem, Hello World", "caption": "", "width": 1479, "height": 931 }, { "type": "paragraph", "html": "mix stream with key value store" }, { "type": "image", "src": "https://cdn-images-1.medium.com/max/800/1*Bij2diYV3vJmZyZFn0foRA.png", "alt": "Nats Jet Strem, Hello World", "caption": "", "width": 921, "height": 400 }, { "type": "heading", "level": 2, "text": "Delete the stream and see the list of data in stream" }, { "type": "code", "lang": "text", "code": "watch nats stream lsnats stream purge NAMEOFSTREAMnats sub --stream CALLBACKS" }, { "type": "heading", "level": 2, "text": "Limits-based Stream in JetStream" }, { "type": "paragraph", "html": "Delivery reliability" } ] }