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    IoT Platform:Operation log

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    IoT Platform:Operation log

    Last Updated:Jun 18, 2026

    After you run the data compression example, you can check the operation logs on the device and in the IoT Platform console to verify the results.

    Prerequisites

    The data compression example for the Link SDK for C must be configured. For more information, see Usage example.

    Device logs

    Check the following execution results on the device.

    • Connection logs.

      The following logs indicate that the device has connected to IoT Platform.

      [1673252439.000][LK-0313] MQTT user calls aiot_mqtt_connect api, connect
[1673252439.000][LK-032A] mqtt host: xxxxxx.xxxxx.xxxxxx.xxxxxxx.com
[1673252439.000][LK-0317] user name: compress_xxxxxxx
[1673252439.000][LK-0318] password: 570D5xxxxxxxxx
success to establish tcp, fd=3
local port: 47622
[1673252439.100][LK-1000] establish mbedtls connection with server(host='xxxxx.xxxxxx.unify.aliyuncs.com', port=[443])
[1673252439.288][LK-1000] success to establish mbedtls connection, (cost 45326 bytes in total, max used 48294 bytes)
[1673252440.111][LK-0313] MQTT connect success in 1109 ms
AIOT_MQTTEVT_CONNECT

    • The device subscribes to the response message topic.

      [1673252440.111][LK-0309] sub: /sys/a1xxxxxx/compress_test_001/codec/topic/update_reply
suback, res: -0x0000, packet id: 1, max qos: 1

    • The device reports the topic list.

      [1673252440.611][LK-0309] pub: /sys/a1xxxxxxx/compress_test_001/codec/topic/update
[LK-030A] > 7B 22 70 61 72 61 6D 73  22 3A 5B 7B 22 74 6F 70 | {"params":[{"top
[LK-030A] > 69 63 22 3A 20 22 2F 61  31 68 45 39 36 7A 66 38 | ic": "/a1xxxxxx
[LK-030A] > 73 34 2F 63 6F 6D 70 72  65 73 73 5F 74 65 73 74 | /compress_test
[LK-030A] > 5F 30 30 31 2F 75 73 65  72 2F 75 70 64 61 74 65 | _001/user/update
[LK-030A] > 22 2C 22 6F 70 65 72 61  74 69 6F 6E 22 3A 20 22 | ","operation": "
[LK-030A] > 64 65 63 6F 6D 70 72 65  73 73 22 2C 22 66 6F 72 | decompress","for
[LK-030A] > 6D 61 74 22 3A 20 22 67  7A 69 70 22 7D 2C 7B 22 | mat": "gzip"},{"
[LK-030A] > 74 6F 70 69 63 22 3A 20  22 2F 73 79 73 2F 61 31 | topic": "/sys/a1
[LK-030A] > 68 45 39 36 7A 66 38 73  34 2F 63 6F 6D 70 72 65 | xxxxxx/compre
[LK-030A] > 73 73 5F 74 65 73 74 5F  30 30 31 2F 74 68 69 6E | ss_test_001/thin
[LK-030A] > 67 2F 65 76 65 6E 74 2F  70 72 6F 70 65 72 74 79 | g/event/property
[LK-030A] > 2F 70 6F 73 74 22 2C 22  6F 70 65 72 61 74 69 6F | /post","operatio
[LK-030A] > 6E 22 3A 20 22 64 65 63  6F 6D 70 72 65 73 73 22 | n": "decompress"
[LK-030A] > 2C 22 66 6F 72 6D 61 74  22 3A 20 22 67 7A 69 70 | ,"format": "gzip
[LK-030A] > 22 7D 2C 7B 22 74 6F 70  69 63 22 3A 20 22 2F 61 | "},{"topic": "/a
[LK-030A] > 31 68 45 39 36 7A 66 38  73 34 2F 63 6F 6D 70 72 | 1xxxxxxx/compr
[LK-030A] > 65 73 73 5F 74 65 73 74  5F 30 30 31 2F 75 73 65 | ess_test_001/use
[LK-030A] > 72 2F 75 70 64 61 74 65  5F 72 65 70 6C 79 22 2C | r/update_reply",
[LK-030A] > 22 6F 70 65 72 61 74 69  6F 6E 22 3A 20 22 63 6F | "operation": "co
[LK-030A] > 6D 70 72 65 73 73 22 2C  22 66 6F 72 6D 61 74 22 | mpress","format"
[LK-030A] > 3A 20 22 67 7A 69 70 22  7D 2C 7B 22 74 6F 70 69 | : "gzip"},{"topi
[LK-030A] > 63 22 3A 20 22 2F 73 79  73 2F 61 31 68 45 39 36 | c": "/sys/a1xxxxx
[LK-030A] > 7A 66 38 73 34 2F 63 6F  6D 70 72 65 73 73 5F 74 | /compress_t
[LK-030A] > 65 73 74 5F 30 30 31 2F  74 68 69 6E 67 2F 65 76 | est_001/thing/ev
[LK-030A] > 65 6E 74 2F 70 72 6F 70  65 72 74 79 2F 70 6F 73 | ent/property/pos
[LK-030A] > 74 5F 72 65 70 6C 79 22  2C 22 6F 70 65 72 61 74 | t_reply","operat
[LK-030A] > 69 6F 6E 22 3A 20 22 63  6F 6D 70 72 65 73 73 22 | ion": "compress"
[LK-030A] > 2C 22 66 6F 72 6D 61 74  22 3A 20 22 67 7A 69 70 | ,"format": "gzip
[LK-030A] > 22 7D 5D 7D                                      | "}]}

    • IoT Platform returns the result.

      [1673252441.266][LK-0309] pub: /sys/a1xxxxxxx/compress_test_001/codec/topic/update_reply
[LK-030A] < 7B 22 63 6F 64 65 22 3A  32 30 30 2C 22 6D 65 73 | {"code":200,"mes
[LK-030A] < 73 61 67 65 22 3A 22 73  75 63 63 65 73 73 22 7D | sage":"success"}
compress update reply code 200, message success

    • The device reports a compressed message.

      The log shows the original message before compression. The keyword compressed indicates that compression is complete.

      [1673252442.611][LK-0309] pub: /sys/a1xxxxxx/compress_test_001/thing/event/property/post
[LK-030A] > 7B 22 69 64 22 3A 22 31  22 2C 22 76 65 72 73 69 | {"id":"1","versi
[LK-030A] > 6F 6E 22 3A 22 31 2E 30  22 2C 22 70 61 72 61 6D | on":"1.0","param
[LK-030A] > 73 22 3A 7B 22 4C 69 67  68 74 53 77 69 74 63 68 | s":{"LightSwitch
[LK-030A] > 22 3A 30 2C 20 22 6D 65  73 73 61 67 65 22 3A 22 | ":0, "message":"
[LK-030A] > 74 68 69 73 20 69 73 20  61 20 74 65 73 74 20 6D | this is a test m
[LK-030A] > 65 73 73 61 67 65 2C 20  74 68 69 73 20 69 73 20 | essage, this is 
[LK-030A] > 61 20 74 65 73 74 20 6D  65 73 73 61 67 65 2C 20 | a test message, 
[LK-030A] > 74 68 69 73 20 69 73 20  61 20 74 65 73 74 20 6D | this is a test m
[LK-030A] > 65 73 73 61 67 65 22 7D  7D                      | essage"}}       
[1673252442.611][LK-2200] compressed [137] --> [103]

    • IoT Platform sends a compressed message to the device.

      The log shows the decompressed message. The keyword decompressed indicates that decompression is complete.

      [1673252442.966][LK-2200] decompressed [105] --> [104]
[1673252442.966][LK-0309] pub: /sys/a1xxxxxxxx/compress_test_001/thing/event/property/post_reply
[LK-030A] < 7B 22 63 6F 64 65 22 3A  32 30 30 2C 22 64 61 74 | {"code":200,"dat
[LK-030A] < 61 22 3A 7B 7D 2C 22 69  64 22 3A 22 31 22 2C 22 | a":{},"id":"1","
[LK-030A] < 6D 65 73 73 61 67 65 22  3A 22 73 75 63 63 65 73 | message":"succes
[LK-030A] < 73 22 2C 22 6D 65 74 68  6F 64 22 3A 22 74 68 69 | s","method":"thi
[LK-030A] < 6E 67 2E 65 76 65 6E 74  2E 70 72 6F 70 65 72 74 | ng.event.propert
[LK-030A] < 79 2E 70 6F 73 74 22 2C  22 76 65 72 73 69 6F 6E | y.post","version
[LK-030A] < 22 3A 22 31 2E 30 22 7D                          | ":"1.0"}

    IoT Platform logs

    After you run the example, check the operation logs in the .

    In the left-side navigation pane, choose Maintenance > Device Log. Select a product to view its message logs.

    Note

    The messages in the logs may appear garbled because IoT Platform stores the compressed message content.

    Click View for a log entry to open the View Details dialog box. The dialog box shows the message topic, such as /sys/{productKey}/{deviceName}/event/property/post, and the message content.

    Next steps

    If the operation log contains errors, check the status code descriptions in the aiot_compress_api.h file to troubleshoot the issue.