Capture

There are various tunable available only via configuration file editing the fie

/opt/fmadio/etc/time.lua

Then in the ["capture"] section editing each field, an example is shown below

["Capture"] =
{
        ["Inline"]      = false,
        ["PortMode"]    = "2x10G",
        ["FlushPktCnt"] = 2000,
        ["FlushPeriod"] = 0,
        ["FlushIdle"]   = 1000000000,
        ["IOPriorityLevel"]   = 90,
        ["IOPriorityHighByte"]   = 1048576,
        ["CaptureSizeMax"]   = 0,
        ["CaptureTimeMax"]   = 0,
},

CaptureSizeMax

When the total daily capture sizes start exceeding 10TB / day file sizes can get bit too large and difficult to work with. This setting sets the maximum size of a single capture, then rolling (losslessly) to a new Capture when the limit is reached.

Example below rolls the capture file every 1TB

 ["CaptureSizeMax"]   = 1e12,

CaptureTimeMax

In addition to maximum size, for large ((10TB+ daily) capture rates a more simpler approach is to roll the capture every 1H. This reduces the size of each capture to something more manageable.

Example below rolls the capture every 1H (units are in nano seconds)

["CaptureTimeMax"]   = 60*60*1e9,

DisableCPUPriority

This setting a debug only as it (potentially) reduces Capture performance, specifically on 100G and higher capture systems. Only enable this if directed by FMADIO Support

 ["DisableCPUPriority"]   = true, 

Confirm the setting by checking log file /mnt/store0/log/stream_capture f20.cur where the following log entries will be seen.

[20210617_175614] fNIC100_RxPollLoop  : 2319 | Disable RxPoll Loop SCHED_RR
[20210617_175614] fNIC100_RxIndexLoop : 2575 | Disable RxIndex 0 Loop SCHED_RR
[20210617_175614] fNIC100_RxIndexLoop : 2575 | Disable RxIndex 0 Loop SCHED_RR
[20210617_175614] fNIC100_RxIndexLoop : 2575 | Disable RxIndex 1 Loop SCHED_RR

FlushPktCnt

This is the number of packets to send (per pipeline) when the Capture pipline has to be flushed. Default is 2000

    ["FlushPktCnt"] = 2000,

FlushPeriod

When in continuous output flush mode this is the period (in nanoseconds) between flushes. Disabling constant period flushing set this to 0. Default is 0 (disable)

    ["FlushPeriod"] = 0,

FlushIdle

This is the idle packet activity timeout. If no new packets are received within this period, the pipeline gets flushed. Default value is 1e9 (1 second)

    ["FlushIdle"]   = 1e9,

ManualOffset

Disables captures midnight roll and instead applies a manual offset to the capture roll time.

Value	Description
0	Midnight roll enabled
nil	Midnight roll enabled
1	Midnight roll disabled
<nanosecond amount>	Manual time offset (e.g. GMT offset -9*60*1e9)

Value in nanoseconds, example is offset of -9 hours backwards (GMT - 9) from the local timezone. This may helpful when the local timeones midnight does not align with an appropriate time to roll the capture file (e.g. a Pool of FMADIO global probes should roll the capture at midnight GMT irrespective of the local timezone)

    ["MidnightRollDisable"]   = -9*60*1e9,