Question about Event Log (object 20) data format #589
Description
Recently, I took a look at Event Log object (id 20) :
And I think that maybe there is issue with log data format ?
My current understanding is that a standard aim to allow interoperability.
In case of Even Log object, to be really interoperable, the LogData ressource format should be clearly defined.
Looking at specification :
| ID | Name | Operations | Instances | Mandatory | Type | Description |
|---|---|---|---|---|---|---|
| 4014 | LogData | R | Single | Mandatory | Opaque | Read Access on that Resource returns the Data Collection associated to the current Object Instance. |
| 4015 | LogDataFormat | RW | Single | Optional | Integer | when set by the Server, this Resource indicates to the Client, what is the Server preferred data format to use when the LogData Resource is returned . when retrieved by the Server, this Resource indicates which specific data format is used when the LogData Resource is returned to the Server 0 or Resource not present : no specific data format (sequence of bytes) 1 : OMA-LwM2M TLV format 2 : OMA-LwM2M JSON format 3: OMA-LwM2M CBOR format [4..99] reserved [100..255] vendor specific data format |
The only "not vendor" specific data format (so which allow interoperability) are :
- OMA-LwM2M TLV format
- OMA-LwM2M JSON format
- OMA-LwM2M CBOR
But I have strictly no idea what could mean to use that format to encode logs ?
Those format are used to encode LWM2M Nodes (Object / Object Instance / Resource / Resource Instance) not for logs ?
There is an example in the specification :
| Resource Name | Resource ID | Value | Notes |
|---|---|---|---|
| LogDataFormat | 4015 | 1 | OMA-LwM2M TLV format |
| LogData | 4014 | 61-7C-E3-01-C1-11- 00-00-05-00-60-18- 18-18-0C-00-01-41- 06-00-02-00-40-0C- 00-00-00-00 |
4545> 2017/8/1 0:46:37.803 - NAS_DBG_TIMER: (00:00:31.685729): LAYER_NAS => LAYER_NAS: action: (TIMER_STOP), prim_id: (EMM_T3410_TIMER_EXPIRY_MSG), duration: 0x00 (0) |
So I tried to decode 617CE301C11100000500601818180C00014106000200400C00000000 using a TLV decoder hoping this will help me to understand but the TLV seems invalid.. and the "notes" doesn't help to understand how TLV should looks like...
So I would appreciate some clarification about that. 🙏
To be totally honest instead of LWM2M data format to encode logs, I was expected more commonly used one like :
- Common Log Format CLF
- Syslog Format : RFC5424
- or even a very simple format defined specifically for this object using plain text, json and/or cbor.
Maybe :
// JSON
{
"timestamp": "2023-10-26T15:34:12Z",
"level": "INFO",
"message": "Request received for product with ID 123",
}
// PLAIN TEXT
TIMESTAMP LEVEL MESSAGE
2023-10-26T15:34:12Z INFO Request received for product with ID 123