From 43e3268adacbb3cd7b173e24c3423cf9d6807526 Mon Sep 17 00:00:00 2001 From: Zdenek Kabelac Date: Fri, 20 Jan 2017 22:53:55 +0100 Subject: [PATCH] dmeventd_thin: rework failure handling Instead of stopping monitoring after couple failing retries, keep monitoring forever, just make larger delays between command retries (ATM upto ~42 minutes). So syslog is not spammed too often, yet commands have a chance to be retried and succeed eventually... --- daemons/dmeventd/plugins/thin/dmeventd_thin.c | 28 +++++++++++++------ 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/daemons/dmeventd/plugins/thin/dmeventd_thin.c b/daemons/dmeventd/plugins/thin/dmeventd_thin.c index bdccac6c3..e1b1f7706 100644 --- a/daemons/dmeventd/plugins/thin/dmeventd_thin.c +++ b/daemons/dmeventd/plugins/thin/dmeventd_thin.c @@ -40,7 +40,7 @@ #define UMOUNT_COMMAND "/bin/umount" -#define MAX_FAILS (10) +#define MAX_FAILS (256) /* ~42 mins between cmd call retry with 10s delay */ #define THIN_DEBUG 0 @@ -55,6 +55,7 @@ struct dso_state { uint64_t known_metadata_size; uint64_t known_data_size; unsigned fails; + unsigned max_fails; int restore_sigset; sigset_t old_sigset; pid_t pid; @@ -475,11 +476,13 @@ void process_event(struct dm_task *dmt, if (state->known_metadata_size != tps->total_metadata_blocks) { state->metadata_percent_check = CHECK_MINIMUM; state->known_metadata_size = tps->total_metadata_blocks; + state->fails = 0; } if (state->known_data_size != tps->total_data_blocks) { state->data_percent_check = CHECK_MINIMUM; state->known_data_size = tps->total_data_blocks; + state->fails = 0; } state->metadata_percent = dm_make_percent(tps->used_metadata_blocks, tps->total_metadata_blocks); @@ -520,6 +523,22 @@ void process_event(struct dm_task *dmt, needs_umount = 1; } + /* Reduce number of _use_policy() calls by power-of-2 factor till frequency of MAX_FAILS is reached. + * Avoids too high number of error retries, yet shows some status messages in log regularly. + * i.e. PV could have been pvmoved and VG/LV was locked for a while... + */ + if (state->fails) { + if (state->fails++ <= state->max_fails) { + log_debug("Postponing frequently failing policy (%u <= %u).", + state->fails - 1, state->max_fails); + return; + } + if (state->max_fails < MAX_FAILS) + state->max_fails <<= 1; + state->fails = needs_policy = 1; /* Retry failing command */ + } else + state->max_fails = 1; /* Reset on success */ + if (needs_policy && _use_policy(dmt, state)) needs_umount = 0; /* No umount when command was successful */ @@ -533,13 +552,6 @@ out: if (tps) dm_pool_free(state->mem, tps); - if (state->fails >= MAX_FAILS) { - log_warn("WARNING: Dropping monitoring of %s. " - "lvm2 command fails too often (%u times in row).", - device, state->fails); - pthread_kill(pthread_self(), SIGALRM); - } - if (new_dmt) dm_task_destroy(new_dmt); } -- 2.43.5