Logging
This page documents the logging configuration
Table of Contents
Configuration file fields
This section is autogenerated from the Rule Schema file.
File log.file
File split size (1 to 512 MB) log.file.split_size
Log file split size in MB. When the file split size is reached a new file is created and the logging continues. Closed log files can be pushed to a server if network is available. Small split sizes may reduce performance.
Type |
Default |
Minimum |
Maximum |
|---|---|---|---|
integer |
50 |
1 |
512 |
File split time period (0 to 86400 seconds, 0 = disable) log.file.split_time_period
Log file split time period in seconds relative to midnight (00:00:00). When a split time is reached a new file is created and the logging continues. Closed log files can be pushed to a server if network is available. Small split time periods may reduce performance.
Type |
Default |
Minimum |
Maximum |
Multiple of |
|---|---|---|---|---|
integer |
0 |
0 |
86400 |
10 |
File split time offset (0 to 86400 seconds) log.file.split_time_offset
Log file split time offset in seconds. This value offsets the split_time_period relative to midnight (00:00:00). The set value shall be less than the split_time_period value.
Type |
Default |
Minimum |
Maximum |
Multiple of |
|---|---|---|---|---|
integer |
0 |
0 |
86400 |
10 |
Cyclic logging log.file.cyclic
With cycling logging mode enabled the oldest log file is deleted when the memory card becomes full, allowing the logging to continue.
Type |
Default |
Options |
|---|---|---|
integer |
1 |
Disable: |
Compression log.compression
Level log.compression.level
Window size used during optional compression. Larger window sizes yield potentially better compression rates, but may reduce logging performance. Compressed log files need to be decompressed prior to processing.
Type |
Default |
Options |
|---|---|---|
integer |
0 |
Disable: |
Encryption log.encryption
State log.encryption.state
Optional log file encryption. Encrypted log files need to be decrypted prior to processing. Decryption requires your encryption password in plain form - if this is lost, the encrypted data cannot be recovered.
Type |
Default |
Options |
|---|---|---|
integer |
0 |
Disable: |
Error Frames log.error_frames
State log.error_frames.state
Specify whether to record error frames. Enabling this can negatively impact performance, as a potentially large number of additional frames may be recorded.
Type |
Default |
Options |
|---|---|---|
integer |
0 |
Disable: |
Configuration explained
This section contains additional information and examples.
File split
File splitting can be based on file size or file size and time:
split_time_period = 0: Split based on size onlysplit_time_period > 0: Split based on both size and time - whichever is reached first
Limits
The file system limits should be considered when configuring the split size and time:
SD-card size
Max
1024sessionsMax
256splits (log files) in each session
Above limits result in a maximum of 1024*256=262144 log files if fully utilised.
If the session count limit is reached, the logger will either:
Stop logging if cyclic logging is disabled1
Delete the oldest session if cyclic logging is enabled
If SD-card becomes full (no more space), the logger will either:
Stop logging if cyclic logging is disabled1
Delete the oldest split file from the oldest session if cyclic logging is enabled
Limit examples
In most cases the SD-card size limit is reached before the session limit. However, some configurations may cause the session count limit to be reached first. Below follows a range of log split configuration examples and the resulting utilization (Util.) of the SD-card space. Configurations resulting in partial utilization are marked in bold2.
8GB SD-card, varying split size, fixed split time:
Card [GB] |
Rate [Msg/s] |
Split size [MB] |
Split time [s] |
Total [days] |
Util. [GB] |
|---|---|---|---|---|---|
8 |
10 |
1 |
3600 |
276.2 |
8.0 |
8 |
100 |
1 |
3600 |
27.6 |
8.0 |
8 |
1000 |
1 |
3600 |
2.8 |
8.0 |
8 |
10 |
10 |
3600 |
276.2 |
8.0 |
8 |
100 |
10 |
3600 |
27.6 |
8.0 |
8 |
1000 |
10 |
3600 |
2.8 |
8.0 |
8 |
10 |
100 |
3600 |
276.2 |
8.0 |
8 |
100 |
100 |
3600 |
27.6 |
8.0 |
8 |
1000 |
100 |
3600 |
2.8 |
8.0 |
32GB SD-card, varying split size, fixed split time:
Card [GB] |
Rate [Msg/s] |
Split size [MB] |
Split time [s] |
Total [days] |
Util. [GB] |
|---|---|---|---|---|---|
32 |
10 |
1 |
3600 |
1104.7 |
32.0 |
32 |
100 |
1 |
3600 |
110.5 |
32.0 |
32 |
1000 |
1 |
3600 |
11.0 |
32.0 |
32 |
10 |
10 |
3600 |
1104.7 |
32.0 |
32 |
100 |
10 |
3600 |
110.5 |
32.0 |
32 |
1000 |
10 |
3600 |
11.0 |
32.0 |
32 |
10 |
100 |
3600 |
1104.7 |
32.0 |
32 |
100 |
100 |
3600 |
110.5 |
32.0 |
32 |
1000 |
100 |
3600 |
11.0 |
32.0 |
8GB SD-card, fixed split size, varying split time:
Card [GB] |
Rate [Msg/s] |
Split size [MB] |
Split time [s] |
Total [days] |
Util. [GB] |
|---|---|---|---|---|---|
8 |
10 |
512 |
10 |
30.3 |
0.9 |
8 |
100 |
512 |
10 |
27.6 |
8.0 |
8 |
1000 |
512 |
10 |
2.8 |
8.0 |
8 |
10 |
512 |
60 |
182.0 |
5.3 |
8 |
100 |
512 |
60 |
27.6 |
8.0 |
8 |
1000 |
512 |
60 |
2.8 |
8.0 |
8 |
10 |
512 |
300 |
276.2 |
8.0 |
8 |
100 |
512 |
300 |
27.6 |
8.0 |
8 |
1000 |
512 |
300 |
2.8 |
8.0 |
32GB SD-card, fixed split size, varying split time:
Card [GB] |
Rate [Msg/s] |
Split size [MB] |
Split time [s] |
Total [days] |
Util. [GB] |
|---|---|---|---|---|---|
32 |
10 |
512 |
10 |
30.3 |
0.9 |
32 |
100 |
512 |
10 |
30.3 |
8.8 |
32 |
1000 |
512 |
10 |
11.0 |
32.0 |
32 |
10 |
512 |
60 |
182.0 |
5.3 |
32 |
100 |
512 |
60 |
110.5 |
32.0 |
32 |
1000 |
512 |
60 |
11.0 |
32.0 |
32 |
10 |
512 |
300 |
910.2 |
26.4 |
32 |
100 |
512 |
300 |
110.5 |
32.0 |
32 |
1000 |
512 |
300 |
11.0 |
32.0 |
Compression
Log files can be compressed on the device during logging using a variant of the LZSS algorithm based on heatshrink. Compressed files will have *.MFC as file extension. A high window size improves compression rates, but may cause message loss on very busy networks.
The table below lists results for J1939 and OBD data with different window size configurations3:
Window size (bytes) |
J1939 % (range) |
OBD % (range) |
|---|---|---|
256 |
49.7 (47.1-51.4) |
32.0 (30.3-32.8) |
512 |
49.5 (46.3-51.6) |
30.2 (29.6-31.1) |
1024 |
41.4 (38.9-45.5) |
30.0 (29.6-30.8) |
Decompression can be done using an implementation of LZSS or using the tools provided with the CANedge.
Note
The split size set in split_size considers the size of the compressed data. I.e. if the split size is 10 MB, the resulting file sizes become 10 MB regardless if compression is used or not.
Encryption
Log files can stored as encrypted (AES-GCM) *.MFE files.
Note
It is recommended to use a 40+ character password for proper encryption
Decryption can be done using an implementation of the PBKDF2 algorithm or using the tools provided with the CANedge.
Error Frames
Enabling error frames will log errors across all interfaces, both CAN and LIN. Note that this can decrease the performance of the device due to the added logging load.
For more information on logging of CAN-bus errors, see CAN errors.