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Safety Core Components

Safety Black Box (SBB)

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The Safety Black Box (SBB) is the audit trail of Safety Core. Components write their errors, fault decisions and safety-event traces to it, for compliance auditing and post-incident analysis. SBB is a small library, libnvpsb.so, that writes each record to the Linux syslog.

SBB: the SEI daemon, the NvPSD Gateway and the MDX client write records through libnvpsb.so to syslog; the container's rsyslog stores them in psf.log and the container output, and the host rsyslog rule stores them in pss.log

Who writes to SBB

Syslog tagComponentWhat it records
NVPSB_PSS_DAEMONSEI daemon (nvpss_daemon)Every audit record of the SEI daemon: source loss, rejection streaks, delivery failures, staging overflows, fusion health, and each accepted report. See Safety Event Integrator (SEI).
nvpsd_gateway, NVPSB_PSD_CLIENTNvPSD Gateway (nvpsd_gateway)Requests received from SEI, synthetic faults, recovery records, SDM registration and refusals, heartbeat tiers and dropped requests. See NvPSD Gateway.
nv_mdx_clientMDX client (mdx_client)Mapping and identity loading, registration, each reported event, dropped events and heartbeat failures.

The client library that event sources use to talk to the SEI daemon also writes its errors through SBB. In SAIM and PCM, which do not set a tag, those lines carry the program name. SAIM, PCM, the reference SDMs, the command receivers and fsicom-agent write their own logs to standard output, standard error or a log file instead; see their component pages.

Record format

Each record is one syslog message with facility LOG_USER, the tag above and the process ID:

 Timestamp: 2026-01-01 12:00:00:123456 Endpoint: NVPSB_PSS_DAEMON Data: <message><detail>
  • Timestamp is the local wall-clock time with microseconds.
  • Endpoint names the component role: NVPSB_PSS_DAEMON for the SEI daemon, NVPSB_PSD_CLIENT for the gateway, NVPSB_PSS_SOURCE for the MDX client.
  • The message and its detail are joined with no separator, for example registration refusedreason=table_full, peer=3.
  • The syslog priority is the record’s level, from EMERG to DEBUG. EMERG and ALERT are reserved for the SEI daemon; any other component’s record at those levels is written at CRIT. SBB itself does not filter by level.

The fields of each audit record are listed in Causes and records.

Where the records land

DeploymentSBB recordsStandard output and error
Docker runtime (launch_hoisa.sh, or docker run of the Safety Core image)The container’s rsyslog writes every syslog message to /var/log/psf/psf.log inside the container and to the container output (docker logs). launch_hoisa.sh mounts the host’s /var/log/psf/psf.log there.Container output (docker logs).
Host (Debian package, launch_hoisa.sh --runtime host)The rsyslog rule /etc/rsyslog.d/99-pss-logs.conf sends the tags nvpss_daemon, nvpsd_gateway, nv_mdx_client, NVPSB_PSS_SOURCE, NVPSB_PSS_SINK, NVPSB_PSS_DAEMON, NVPSB_PSD_CLIENT and NVPSB_SDM_CLIENT to /var/log/psf/pss.log and stops there, so these records do not reach /var/log/syslog.launch_hoisa.sh appends the output of the SEI daemon, the gateway and the MDX client to /var/log/psf/psf.log.
  • On a host, the package installs the rule and an empty /var/log/psf/pss.log (mode 0666), but does not restart rsyslog. Restart rsyslog after installing the package so that the rule takes effect.
  • On a host, the SBB records and the process output of the same component are in two files: pss.log and psf.log. Read both when you investigate a fault.
  • Transport diagnostics, such as a refused peer GID or a socket-buffer shortfall, are written to standard error, not to SBB.
  • Where each component’s own log lands is listed in Troubleshooting.

Library interface

libnvpsb.so has three functions:

FunctionPurpose
NvPSBInitialize(ident, endpoint)Opens syslog with the tag ident and records the endpoint role.
NvPSBWriteData(level, data, additionalInfo)Writes one record.
NvPSBExit()Closes syslog.

The endpoint roles are NVPSB_PSS_SOURCE, NVPSB_PSS_SINK, NVPSB_PSS_DAEMON, NVPSB_PSD_CLIENT and NVPSB_SDM_CLIENT. The functions return an NvPSBErr (NVPSB_SUCCESS, NVPSB_FAIL, NVPSB_NO_RSP or NVPSB_UNINITIALIZED); the levels are the syslog severities, NVPSB_LOG_EMERG to NVPSB_LOG_DEBUG. The SBB header is not part of the development package, so the library is for Safety Core components; a custom component can write to syslog directly.