Thanks for the help, Chris. Actually, when i first saw this problem I think it was a forum post which tipped me off that /etc/issue was the cause. But I have been unable to find that post again.
Here is what the log looks like when the poller is failing:
...
...
[2017-08-31 13:42:42] [DEBUG ] [conf] Line [79] is Section [lshnap006]
[2017-08-31 13:42:42] [DEBUG ] [conf] Line [80] in Section [lshnap006] has Key/Value pair [hostname]=[10.24.192.8]
[2017-08-31 13:42:42] [DEBUG ] [conf] Line [81] in Section [lshnap006] has Key/Value pair [group]=[LSH]
[2017-08-31 13:42:42] [DEBUG ] [conf] Line [82] in Section [lshnap006] has Key/Value pair [username]=[harvest]
[2017-08-31 13:42:42] [DEBUG ] [conf] Line [83] in Section [lshnap006] has Key/Value pair [password]=[**********]
[2017-08-31 13:42:42] [DEBUG ] [conf] Line [84] in Section [lshnap006] has Key/Value pair [template]=[7dot-8.2.0-cifs-stats.conf]
[2017-08-31 13:42:42] [NORMAL ] [main] Poller will monitor a [FILER] at [10.24.65.185:443]
[2017-08-31 13:42:42] [NORMAL ] [main] Poller will use [password] authentication with username [harvest] and password [**********]
[2017-08-31 13:42:42] [DEBUG ] [sysinfo] Updating system-info cache
[2017-08-31 13:42:42] [DEBUG ] [connect] Using HTTP/1.0 for communication (either set earlier or only version supported by SDK).
[2017-08-31 13:42:42] [WARNING] [sysinfo] Update of system-info cache DOT Version failed with reason: Couldn't find end of Start Tag netapp
[2017-08-31 13:42:42] [WARNING] [main] system-info update failed; will try again in 10 seconds.
[2017-08-31 13:42:52] [DEBUG ] [sysinfo] Updating system-info cache
[2017-08-31 13:42:52] [DEBUG ] [connect] Using HTTP/1.0 for communication (either set earlier or only version supported by SDK).
[2017-08-31 13:42:53] [WARNING] [sysinfo] Update of system-info cache DOT Version failed with reason: Couldn't find end of Start Tag netapp
[2017-08-31 13:42:53] [WARNING] [main] system-info update failed; will try again in 10 seconds.
I have confirmed that the problem is being caused by the single-quote being used as an apostrophe. If I just remove that character from issue, the poller starts OK. It is not surprising, because any shell utility which parses text can easily get confused when it encounters a quote and goes looking forever for the matching end-quote.
Here is the problematic /etc/issue (sanitized). There is a single-quote on the first line.
CONSISTENT WITH XXXXX'S POLICY ON PRIVACY, MESSAGES AND OTHER
DOCUMENTS ON THE NETWORK MAY BE REVIEWED BY XXXXX MANAGEMENT
UNDER THE FOLLOWING CIRCUMSTANCES: WHEN AUTHORIZED BY THE
CREATOR OR RECEIVER; WHERE A BUSINESS-RELATED NEED EXISTS;
WHEN REQUIRED BY REGULATORY OR LEGAL AUTHORITY; OR WHEN
REQUESTED BY XXXXX COUNSEL TO PROTECT THE LEGAL INTERESTS
OF XXXXX.
USE OF THE SYSTEM BY XXXXX PERSONNEL OTHER THAN FOR BUSINESS
PURPOSES MAY SUBJECT THE USER TO DISCIPLINARY ACTION, INCLUDING
DISCHARGE.
Another detail: once the pollers are started, they will continue to run OK even though the /etc/issue file is returned to its 'problem' state with the ' character. This tells me that it is something being evaluated or stored at startup.
You may be able to reproduce the problem by creating /etc/issue with one single-quote character in it