Environment variables (advanced or temporary options)

• DATADIST_FEE_MASK=0xffff Apply the mask if StfBuilder is configured to use the FeeID field as a O2::Subspecification (O2::Subspec = (RDH::FeeID & DATADIST_FEE_MASK))

• DATADIST_FILE_READ_COUNT=N Terminate after injecting set number of TF files. Data set will be repeated if necessary. Number of TimeFrames will be DATADIST_FILE_READ_COUNT x Number of TFs per file.

• DATADIST_DEBUG_DPL_CHAN When defined, data sent to DPL will be checked for consistency with the O2 data model. Note: will be slow with larger TimeFrames.

Shared memory:

• DATADIST_NO_MLOCK Disable locking of the shared memory segments. Only use in testing and development!

• DATADIST_SHM_ZERO When defined, shared memory segment will be zeroed before use. Because of large performance impact, only use to check for memory corruption, not in production.

• DATADIST_SHM_ZERO_CHECK Define to enable checking for memory corruption in unmanaged region. Each de-allocated message will be checked for write-past-end corruption.

Consul parameter for online runs

DataDistribution Global

• DataDistNetworkTransport (fmq|ucx) Use select transport for FLP-EPN data transport

StfBuilder

• NumPagesInTopologicalStf (128) Page aggregation for topological runs. Larger number of pages decreases FLP-EPN interaction rate (better performance)

StfSender

• StfBufferSizeMB (MegaBytes) Define size of DataDist buffer on FLP. Default is 32768 (MiB)

• UcxRdmaGapB (8192 Bytes) Allowed gap between two messages of the same region when creating RMA txgs. Larger gap creates fewer transactions, but can increase the amount of transferred data.

• UcxStfSenderThreadPoolSize (8) Size of StfSender tread pool. Default 8. Threads are not CPU intensive, they enable simultaneous transfers.

TfBuilder

• MaxNumStfTransfers (100) Define maximum number of concurrent STF transfers. Helps with long tails of TCP transfers.

• UcxTfBuilderThreadPoolSize (2) Size of receiver tread pool. Best to keep low, 1-4.

TfScheduler

• MaxNumTfsInBuilding (25) Define maximum number of concurrent TFs in building per TfBuilder

• BuildIncompleteTfs (true) Decision wether to build or drop incomplete TFs

• StaleTfTimeoutMs (1000 ms) An incomplete TF is considered stale when the following timeout expires after the last STF is reported.

• IncompleteTfsMaxCnt (100) Max number of incomplete TFs to keep before considering them stale