The syntax of this new commands are:
enable agent <backend>/<server>
disable agent <backend>/<server>
These commands allow temporarily stopping and subsequently
re-starting an auxiliary agent check. The effect of this is as follows:
New checks are only initialised when the agent is in the enabled. Thus,
disable agent will prevent any new agent checks from begin initiated until
the agent re-enabled using enable agent.
When an agent is disabled the processing of an auxiliary agent check that
was initiated while the agent was set as enabled is as follows: All
results that would alter the weight, specifically "drain" or a weight
returned by the agent, are ignored. The processing of agent check is
otherwise unchanged.
The motivation for this feature is to allow the weight changing effects
of the agent checks to be paused to allow the weight of a server to be
configured using set weight without being overridden by the agent.
Signed-off-by: Simon Horman <ho...@verge.net.au>
---
v7
* Manual rebase
* Use enable|disable agent <backend>/<server> instead of
set agent <backend>/<server> pause|unpause.
- This is a reasonably trivial re-write of most of the patch
* Rename patch from "MEDIUM: Add set agent pause|unpause unix socket command"
to "MEDIUM: Add enable and disable agent unix socket commands"
* Use CHK_STATE_DISABLED instead of CHK_DISABLED
This is consistent with CHK_STATE_RUNNING which was
previously named CHK_RUNNING
* Correct typos in comment
* Consistently don't call server_parse_weight_change_request() if stopped
Status: pending
Notes by Willy on v6 of
"MEDIUM: Add set agent pause|unpause unix socket command":
I think that instead of setting the agent status to pause/unpaused, we'd
rather reuse the same principle as we currently have with servers :
enable agent <backend>/<server>
disable agent <backend>/<server>
OK for the rest of course.
v6
* First post
---
doc/configuration.txt | 31 +++++++++++++++++++++++++++++++
include/types/server.h | 1 +
src/checks.c | 28 ++++++++++++++++++++++++----
src/dumpstats.c | 24 +++++++++++++++++++++++-
4 files changed, 79 insertions(+), 5 deletions(-)
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 8094bab..f54dbd2 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -12051,6 +12051,28 @@ clear table <table> [ data.<type> <operator> <value> ]
| [ key <key> ]
$ echo "show table http_proxy" | socat stdio /tmp/sock1
>>> # table: http_proxy, type: ip, size:204800, used:1
+enable agent <backend>/<server>
+ Mark the auxiliary agent check as temporarily stopped.
+
+ In the case where an agent check is being run as a auxiliary check, due
+ to the agent-check parameter of a server directive, new checks are only
+ initialised when the agent is in the enabled. Thus, disable agent will
+ prevent any new agent checks from begin initiated until the agent
+ re-enabled using enable agent.
+
+ When an agent is disabled the processing of an auxiliary agent check that
+ was initiated while the agent was set as enabled is as follows: All
+ results that would alter the weight, specifically "drain" or a weight
+ returned by the agent, are ignored. The processing of agent check is
+ otherwise unchanged.
+
+ The motivation for this feature is to allow the weight changing effects
+ of the agent checks to be paused to allow the weight of a server to be
+ configured using set weight without being overridden by the agent.
+
+ This command is restricted and can only be issued on sockets configured for
+ level "admin".
+
disable frontend <frontend>
Mark the frontend as temporarily stopped. This corresponds to the mode which
is used during a soft restart : the frontend releases the port but can be
@@ -12082,6 +12104,15 @@ disable server <backend>/<server>
This command is restricted and can only be issued on sockets configured for
level "admin".
+enable agent <backend>/<server>
+ Resume auxiliary agent check that was temporarily stopped.
+
+ See "disable agent" for details of the effect of temporarily starting
+ and stopping an auxiliary agent.
+
+ This command is restricted and can only be issued on sockets configured for
+ level "admin".
+
enable frontend <frontend>
Resume a frontend which was temporarily stopped. It is possible that some of
the listening ports won't be able to bind anymore (eg: if another process
diff --git a/include/types/server.h b/include/types/server.h
index 51f70de..96c4318 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -74,6 +74,7 @@
/* check flags */
#define CHK_STATE_RUNNING 0x0001 /* this check is currently running */
+#define CHK_STATE_DISABLED 0x0002 /* this check is currently
administratively disabled */
/* various constants */
#define SRV_UWGHT_RANGE 256
diff --git a/src/checks.c b/src/checks.c
index 2113c8c..eb8ce81 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -836,7 +836,6 @@ static void event_srv_chk_w(struct connection *conn)
goto out_wakeup;
}
-
/*
* This function is used only for server health-checks. It handles the server's
* reply to an HTTP request, SSL HELLO or MySQL client Auth. It calls
@@ -992,19 +991,36 @@ static void event_srv_chk_r(struct connection *conn)
short status = HCHK_STATUS_L7RSP;
const char *desc = "Unknown feedback string";
const char *down_cmd = NULL;
+ int disabled;
if (!done)
goto wait_more_data;
cut_crlf(check->bi->data);
+ /*
+ * The agent may have been disabled after a check was
+ * initialised. If so, ignore weight changes and drain
+ * settings from the agent. Note that the setting is
+ * always present in the state of the agent the server,
+ * regardless of if the agent is being run as a primary or
+ * secondary check. That is, regardless of if the check
+ * parameter of this function is the agent or check field
+ * of the server.
+ */
+ disabled = check->server->agent.state & CHK_STATE_DISABLED;
+
if (strchr(check->bi->data, '%')) {
+ if (disabled)
+ break;
desc = server_parse_weight_change_request(s,
check->bi->data);
if (!desc) {
status = HCHK_STATUS_L7OKD;
desc = check->bi->data;
}
} else if (!strcasecmp(check->bi->data, "drain")) {
+ if (disabled)
+ break;
desc = server_parse_weight_change_request(s, "0%");
if (!desc) {
desc = "drain";
@@ -1315,10 +1331,14 @@ static struct task *process_chk(struct task *t)
if (!expired) /* woke up too early */
return t;
- /* we don't send any health-checks when the proxy is stopped or
when
- * the server should not be checked.
+ /* we don't send any health-checks when the proxy is
+ * stopped, the server should not be checked or the check
+ * is disabled.
*/
- if (!(s->state & SRV_CHECKED) || s->proxy->state ==
PR_STSTOPPED || (s->state & SRV_MAINTAIN))
+ if (!(s->state & SRV_CHECKED) ||
+ s->proxy->state == PR_STSTOPPED ||
+ (s->state & SRV_MAINTAIN) ||
+ (check->state & CHK_STATE_DISABLED))
goto reschedule;
/* we'll initiate a new check */
diff --git a/src/dumpstats.c b/src/dumpstats.c
index 3d60b09..adac834 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -1294,6 +1294,17 @@ static int stats_sock_parse_request(struct
stream_interface *si, char *line)
}
}
else if (strcmp(args[0], "enable") == 0) {
+ if (strcmp(args[1], "agent") == 0) {
+ struct server *sv;
+
+ sv = expect_server_admin(s, si, args[2]);
+ if (!sv)
+ return 1;
+
+ sv->agent.state &= ~CHK_STATE_DISABLED;
+
+ return 1;
+ }
if (strcmp(args[1], "server") == 0) {
struct server *sv;
@@ -1355,7 +1366,18 @@ static int stats_sock_parse_request(struct
stream_interface *si, char *line)
}
}
else if (strcmp(args[0], "disable") == 0) {
- if (strcmp(args[1], "server") == 0) {
+ if (strcmp(args[1], "agent") == 0) {
+ struct server *sv;
+
+ sv = expect_server_admin(s, si, args[2]);
+ if (!sv)
+ return 1;
+
+ sv->agent.state |= CHK_STATE_DISABLED;
+
+ return 1;
+ }
+ else if (strcmp(args[1], "server") == 0) {
struct server *sv;
sv = expect_server_admin(s, si, args[2]);
--
1.8.4
