This time I caught it on the test stand with better error reporting.

Test stand code error:

Mar 24 10:14:29 conlog-test-master conlogd: Channel Access Exception: Channel Name: Unavailable, Native Type: Unavailable, Native Count: 0, Read Access: Unavailable, Write Access: Unavailable, IOC: Unavailable, Message: Virtual circuit disconnect, Context: h1asc0.cds.ligo-wa.caltech.edu:60755, Requested Type: TYPENOTCONN, Requested Count: 0, Source File: ../cac.cpp, Line Number: 1214
Mar 24 10:55:15 conlog-test-master conlogd: ../database.cpp: 661: insert_dbr_string_value_execute: Error executing m_p_insert_dbr_string_value_prep_stmt. Parameters: H1:SYS-MOTION_Y_SHUTTER_A_NAME, 1427219715488583185, 0, �, 0, 0.
Mar 24 10:55:15 conlog-test-master conlogd: ../conlog.cpp: 314: process_cac_messages: MySQL Exception: Error: Incorrect string value: 'xC0' for column 'value' at row 1: Error code: 1366: SQLState: HY000: Exiting.
Mar 24 10:55:16 conlog-test-master conlogd: ../conlog.cpp: 346: process_cas: Exception: boost: mutex lock failed in pthread_mutex_lock: Invalid argument Exiting.

Seems to have non ascii characters in the value of the H1:SYS-MOTION_Y_SHUTTER_A_NAME channel.

Production code error:

Mar 24 10:14:29 h1conlog1-master conlog: Channel Access Exception: Channel Name: Unavailable, Native Type: Unavailable, Native Count: 0, Read Access: Unavailable, Write Access: Unavailable, IOC: Unavailable, Message: Virtual circuit disconnect, Context: h1asc0.cds.ligo-wa.caltech.edu:60755, Requested Type: TYPENOTCONN, Requested Count: 0, Source File: ../cac.cpp, Line Number: 1214
Mar 24 10:17:01 h1conlog1-master CRON[21576]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Mar 24 10:39:01 h1conlog1-master CRON[21583]: (root) CMD (  [ -x /usr/lib/php5/maxlifetime ] && [ -x /usr/lib/php5/sessionclean ] && [ -d /var/lib/php5 ] && /usr/lib/php5/sessionclean /var/lib/php5 $(/usr/lib/php5/maxlifetime))
Mar 24 10:55:25 h1conlog1-master conlog: ../conlog.cpp: 301: process_cac_messages: MySQL Exception: Error: Incorrect string value: 'xEC>xBF' for column 'value' at row 1: Error code: 1366: SQLState: HY000: Exiting.
Mar 24 10:55:26 h1conlog1-master conlog: ../conlog.cpp: 331: process_cas: Exception: boost: mutex lock failed in pthread_mutex_lock: Invalid argument Exiting.

They may have failed on different channels, but this narrows it down.