Add Collector log (#14309)

3 files changed, 24 insertions, 12 deletions

diff --git a/daemon/README.md b/daemon/README.md
index 45eb27ae27..911075df52 100644
--- a/daemon/README.md
+++ b/daemon/README.md
@@ -210,25 +210,22 @@ You can send commands during runtime via [netdatacli](/cli/README.md).
 
 ## Log files
 
-Netdata uses 3 log files:
+Netdata uses 4 log files:
 
 1.  `error.log`
-2.  `access.log`
-3.  `debug.log`
+2.  `collector.log`
+3.  `access.log`
+4.  `debug.log`
 
-Any of them can be disabled by setting it to `/dev/null` or `none` in `netdata.conf`. By default `error.log` and
-`access.log` are enabled. `debug.log` is only enabled if debugging/tracing is also enabled (Netdata needs to be compiled
-with debugging enabled).
+Any of them can be disabled by setting it to `/dev/null` or `none` in `netdata.conf`. By default `error.log`,
+`collector.log`, and `access.log` are enabled. `debug.log` is only enabled if debugging/tracing is also enabled
+(Netdata needs to be compiled with debugging enabled).
 
 Log files are stored in `/var/log/netdata/` by default.
 
 ### error.log
 
-The `error.log` is the `stderr` of the `netdata` daemon and all external plugins
-run by `netdata`.
-
-So if any process, in the Netdata process tree, writes anything to its standard error,
-it will appear in `error.log`.
+The `error.log` is the `stderr` of the `netdata` daemon .
 
 For most Netdata programs (including standard external plugins shipped by netdata), the following lines may appear:
 
@@ -243,6 +240,16 @@ program continues to run.
 
 When a Netdata program cannot run at all, a `FATAL` line is logged.
 
+### collector.log
+
+The `collector.log` is the `stderr` of all [collectors](https://github.com/netdata/netdata/blob/master/collectors/COLLECTORS.md)
+ run by `netdata`.
+
+So if any process, in the Netdata process tree, writes anything to its standard error,
+it will appear in `collector.log`.
+
+Data stored inside this file follows pattern already described for `error.log`.
+
 ### access.log
 
 The `access.log` logs web requests. The format is:
diff --git a/daemon/global_statistics.c b/daemon/global_statistics.c
index cb89ed01d9..ea658435fa 100644
--- a/daemon/global_statistics.c
+++ b/daemon/global_statistics.c
@@ -3783,7 +3783,7 @@ static int read_thread_cpu_time_from_proc_stat(pid_t pid __maybe_unused, kernel_
 
     // (re)open the procfile to the new filename
     bool set_quotes = (ff == NULL) ? true : false;
-    ff = procfile_reopen(ff, filename, NULL, PROCFILE_FLAG_DEFAULT);
+    ff = procfile_reopen(ff, filename, NULL, PROCFILE_FLAG_ERROR_ON_ERROR_LOG);
     if(unlikely(!ff)) return -1;
 
     if(set_quotes)
diff --git a/daemon/main.c b/daemon/main.c
index 1eff318f1a..608985bddf 100644
--- a/daemon/main.c
+++ b/daemon/main.c
@@ -831,6 +831,9 @@ static void log_init(void) {
     snprintfz(filename, FILENAME_MAX, "%s/error.log", netdata_configured_log_dir);
     stderr_filename    = config_get(CONFIG_SECTION_LOGS, "error",  filename);
 
+    snprintfz(filename, FILENAME_MAX, "%s/collector.log", netdata_configured_log_dir);
+    stdcollector_filename = config_get(CONFIG_SECTION_LOGS, "collector", filename);
+
     snprintfz(filename, FILENAME_MAX, "%s/access.log", netdata_configured_log_dir);
     stdaccess_filename = config_get(CONFIG_SECTION_LOGS, "access", filename);
 
@@ -1320,6 +1323,8 @@ int main(int argc, char **argv) {
     usec_t started_ut = now_monotonic_usec();
     usec_t last_ut = started_ut;
     const char *prev_msg = NULL;
+    // Initialize stderror avoiding coredump when info() or error() is called
+    stderror = stderr;
 
     int i;
     int config_loaded = 0;