Last Modified: Sep 13, 2023
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
11.6.1
Fixed In:
13.1.0, 11.6.2
Opened: Mar 01, 2017 Severity: 3-Major Related Article:
K10776106
Repeated entries in the ltm log will show a completion-code error (comp_code=4) as in the following: Zip engine ctx eviction (comp_code=4): ctx dropped.
False errors can appear: o In fields of tmctl rst_cause_stat table, false stats counters will increment for compression and packet errors. o Log entries with the "Zip engine... (comp_code=4)" appear in ltm log. Monitors observing the ltm log or stats in the tmctl rst_cause_stat table will see false positives.
The problem occurs when a flow that requests DEFLATE decompression is terminated when the compression engine is still in the middle of working on an incomplete DEFLATE block.
Disable hardware acceleration.
A new tcl variable, nitrox::comp_suppress_itrunc, was added. It defaults to NO which yields legacy behavior. Setting it to YES causes comp_code=4 (ITRUNC) errors to not propagate as an error. To enable the feature, add the following line to /config/tmm_init.tcl: nitrox::comp_suppress_itrunc yes You will have to restart tmm for the change to take effect.