Java8.
jstat column output is not stable across JVM versions (technically
version of jstat binary used).
New columns are added not add the end of column list but in the middle
breaking access via constant index.
Following table shows the known columns per version:
Oracle JDK / OpenJDK 1.5 .. 1.7
S0C S1C S0U S1U EC EU OC OU PC PU YGC YGCT FGC FGCT GCT
Openjdk 1.8 .. 10
S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT
Openjdk 11 .. 12
S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT CGC CGCT GCT
Earlier commit here added support for java8+ but using version checking
if version == 1.5 > Use pre-java8 column format, else new format.
As fixing java6+7 would mean more version comparison which is ugly this
cmomit changes retrival logic to the following;
a.) Parse first line jstat output to find position for each label
b.) Then use that position to fetch value from 2nd line
That way code auto-adjusts to any ordering change without needing any
java version specific code or checks.
On the way fix 'Permanent Used' value reporting for java8 which was
broken (missing variable rename from PU -> MU when java8 support was
added).
* fix spelling mistake (thanks, codespell)
* do not hide exit code of command substitution via "local" (thanks, shellcheck)
* avoid access of potentially undefined variables (thanks, shellcheck)
* fix tabs/spaces
* avoid variable substitution in arithmetic substitution
* reduce number of successive blank lines at the top level down to two
* simplify evaluation of "printenv" output
Plugins available:
* unifi_api - Providing the following graphs:
* unifi_clients_by_device - Count the number of clients connected on a per-device basis
* unifi_clients_by_network - Count the number of clients connected to each named network
* unifi_device_stats - Get basic stats from each unifi device - cpu, memory, load average, and uptime
* unifi_xfer_by_device - Transfer stats on a per-device basis
* unifi_xfer_by_network - Transfer stats on a per-network basis
* unifi_xfer_by_port - Transfer stats per switch port
* unifi_xfer_by_uplink - Overall transfer with speedtest stats
Don't exit with error if cache file is missing, instead refrain from sending values and daemonize() in an attempt to generate one.
Invocation using 'config' before generation is successful will fail, as mentioned in #914, but configuration will get picked up as soon as it is present.
Various plugins still followed the old (before 2009?) convention of using
a non-zero exitcode for indicating "no". Most of these (obvious) occasions
should be fixed now.
