commit 105b94b75b51376128037cab05b930c4e4c15497 Author: Nick Mathewson nickm@torproject.org Date: Mon Jan 10 14:11:22 2011 -0500
Add Maxima lists to bandwidth state.
Right now, Tor routers don't save the maxima values from the bw_history_t between sessions. That's no good, since we use those values to determine bandwidth. This code adds a new BWHist.*Maximum set of values to the state file. If they're not present, we estimate them by taking the observed total bandwidth and dividing it by the period length, which provides a lower bound.
This should fix bug 1863. I'm calling it a feature. --- changes/1863_bwhist | 8 +++++- src/or/config.c | 4 +++ src/or/or.h | 8 +++++- src/or/rephist.c | 65 +++++++++++++++++++++++++++++++++++++------------- 4 files changed, 66 insertions(+), 19 deletions(-)
diff --git a/changes/1863_bwhist b/changes/1863_bwhist index b9e8ef4..b942509 100644 --- a/changes/1863_bwhist +++ b/changes/1863_bwhist @@ -1,3 +1,10 @@ + o Minor features + - Servers now save observed maximum bandwidth throughput rates + to their state file (along with total usage, which was already + saved) so that they can determine their correct estimated + bandwidth on restart. Resolves bug 1863, where Tor servers + would reset their estimated bandwidth to 0 after restarting. + o Minor bugfixes - Fix a bug in banwidth history state parsing that could have been triggered if a future version of Tor ever changed the timing @@ -7,4 +14,3 @@ error parsing any bw history value from the state file. Bugfix on Tor 0.2.2.15-alpha.
- diff --git a/src/or/config.c b/src/or/config.c index 17d776e..78978dc 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -443,15 +443,19 @@ static config_var_t _state_vars[] = { V(BWHistoryReadEnds, ISOTIME, NULL), V(BWHistoryReadInterval, UINT, "900"), V(BWHistoryReadValues, CSV, ""), + V(BWHistoryReadMaxima, CSV, ""), V(BWHistoryWriteEnds, ISOTIME, NULL), V(BWHistoryWriteInterval, UINT, "900"), V(BWHistoryWriteValues, CSV, ""), + V(BWHistoryWriteMaxima, CSV, ""), V(BWHistoryDirReadEnds, ISOTIME, NULL), V(BWHistoryDirReadInterval, UINT, "900"), V(BWHistoryDirReadValues, CSV, ""), + V(BWHistoryDirReadMaxima, CSV, ""), V(BWHistoryDirWriteEnds, ISOTIME, NULL), V(BWHistoryDirWriteInterval, UINT, "900"), V(BWHistoryDirWriteValues, CSV, ""), + V(BWHistoryDirWriteMaxima, CSV, ""),
V(TorVersion, STRING, NULL),
diff --git a/src/or/or.h b/src/or/or.h index cb36126..e0f8bab 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -2856,19 +2856,25 @@ typedef struct { * bandwidth usage. The "Interval" fields hold the granularity, in seconds, * of the entries of Values. The "Values" lists hold decimal string * representations of the number of bytes read or written in each - * interval. */ + * interval. The "Maxima" list holds decimal strings describing the highest + * rate achieved during the interval. + */ time_t BWHistoryReadEnds; int BWHistoryReadInterval; smartlist_t *BWHistoryReadValues; + smartlist_t *BWHistoryReadMaxima; time_t BWHistoryWriteEnds; int BWHistoryWriteInterval; smartlist_t *BWHistoryWriteValues; + smartlist_t *BWHistoryWriteMaxima; time_t BWHistoryDirReadEnds; int BWHistoryDirReadInterval; smartlist_t *BWHistoryDirReadValues; + smartlist_t *BWHistoryDirReadMaxima; time_t BWHistoryDirWriteEnds; int BWHistoryDirWriteInterval; smartlist_t *BWHistoryDirWriteValues; + smartlist_t *BWHistoryDirWriteMaxima;
/** Build time histogram */ config_line_t * BuildtimeHistogram; diff --git a/src/or/rephist.c b/src/or/rephist.c index f0dd451..a3a2bab 100644 --- a/src/or/rephist.c +++ b/src/or/rephist.c @@ -1261,8 +1261,12 @@ add_obs(bw_array_t *b, time_t when, uint64_t n) /* If we're currently adding observations for an earlier second than * 'when', advance b->cur_obs_time and b->cur_obs_idx by an * appropriate number of seconds, and do all the other housekeeping */ - while (when>b->cur_obs_time) + while (when>b->cur_obs_time) { + /* Doing this one second at a time is potentially inefficient, if we start + with a state file that is very old. Fortunately, it doesn't seem to + show up in profiles, so we can just ignore it for now. */ advance_obs(b); + }
b->obs[b->cur_obs_idx] += n; b->total_in_period += n; @@ -1497,15 +1501,21 @@ static void rep_hist_update_bwhist_state_section(or_state_t *state, const bw_array_t *b, smartlist_t **s_values, + smartlist_t **s_maxima, time_t *s_begins, int *s_interval) { - char buf[20*NUM_TOTALS + 1], *cp; + char *cp; + int i,j;
if (*s_values) { SMARTLIST_FOREACH(*s_values, char *, val, tor_free(val)); smartlist_free(*s_values); } + if (*s_maxima) { + SMARTLIST_FOREACH(*s_values, char *, val, tor_free(val)); + smartlist_free(*s_maxima); + } if (! server_mode(get_options())) { /* Clients don't need to store bandwidth history persistently; * force these values to the defaults. */ @@ -1519,18 +1529,30 @@ rep_hist_update_bwhist_state_section(or_state_t *state, *s_begins = 0; *s_interval = 900; *s_values = smartlist_create(); + *s_maxima = smartlist_create(); return; } *s_begins = b->next_period; *s_interval = NUM_SECS_BW_SUM_INTERVAL; - cp = buf; - cp += rep_hist_fill_bandwidth_history(cp, sizeof(buf), b); - tor_snprintf(cp, sizeof(buf)-(cp-buf), - cp == buf ? U64_FORMAT : ","U64_FORMAT, - U64_PRINTF_ARG(b->total_in_period)); + *s_values = smartlist_create(); - if (server_mode(get_options())) - smartlist_split_string(*s_values, buf, ",", SPLIT_SKIP_SPACE, 0); + *s_maxima = smartlist_create(); + /* Set i to first position in circular array */ + i = (b->num_maxes_set <= b->next_max_idx) ? 0 : b->next_max_idx; + for (j=0; j < b->num_maxes_set; ++j,++i) { + uint64_t maxval; + if (i > NUM_TOTALS) + i = 0; + tor_asprintf(&cp, U64_FORMAT, U64_PRINTF_ARG(b->totals[i] & ~0x3ff)); + smartlist_add(*s_values, cp); + maxval = b->maxima[i] / NUM_SECS_ROLLING_MEASURE; + tor_asprintf(&cp, U64_FORMAT, U64_PRINTF_ARG(maxval & ~0x3ff)); + smartlist_add(*s_maxima, cp); + } + tor_asprintf(&cp, U64_FORMAT, U64_PRINTF_ARG(b->total_in_period & ~0x3ff)); + smartlist_add(*s_values, cp); + tor_asprintf(&cp, U64_FORMAT, U64_PRINTF_ARG(b->max_total & ~0x3ff)); + smartlist_add(*s_maxima, cp); }
/** Update <b>state</b> with the newest bandwidth history. */ @@ -1541,6 +1563,7 @@ rep_hist_update_state(or_state_t *state) rep_hist_update_bwhist_state_section(state,\ (arrname),\ &state->BWHistory ## st ## Values, \ + &state->BWHistory ## st ## Maxima, \ &state->BWHistory ## st ## Ends, \ &state->BWHistory ## st ## Interval)
@@ -1560,6 +1583,7 @@ rep_hist_update_state(or_state_t *state) static int rep_hist_load_bwhist_state_section(bw_array_t *b, const smartlist_t *s_values, + const smartlist_t *s_maxima, const time_t s_begins, const int s_interval) { @@ -1567,8 +1591,9 @@ rep_hist_load_bwhist_state_section(bw_array_t *b, int retval = 0; time_t start;
- uint64_t v; - int i,ok; + uint64_t v, mv; + int i,ok,ok_m; + int have_maxima = (smartlist_len(s_values) == smartlist_len(s_maxima));
if (s_values && s_begins >= now - NUM_SECS_BW_SUM_INTERVAL*NUM_TOTALS) { start = s_begins - s_interval*(smartlist_len(s_values)); @@ -1578,12 +1603,22 @@ rep_hist_load_bwhist_state_section(bw_array_t *b, b->next_period = start + NUM_SECS_BW_SUM_INTERVAL; SMARTLIST_FOREACH_BEGIN(s_values, const char *, cp) { v = tor_parse_uint64(cp, 10, 0, UINT64_MAX, &ok, NULL); - if (!ok) { + if (have_maxima) { + const char *maxstr = smartlist_get(s_maxima, cp_sl_idx); + mv = tor_parse_uint64(maxstr, 10, 0, UINT64_MAX, &ok_m, NULL); + mv *= NUM_SECS_ROLLING_MEASURE; + } else { + /* No maxima known; guess average rate to be conservative. */ + mv = v / s_interval; + } + if (!ok || !ok_m) { retval = -1; log_notice(LD_HIST, "Could not parse '%s' into a number.'", cp); } + if (start < now) { add_obs(b, start, v); + b->max_total = mv; /* This will result in some fairly choppy history if s_interval * is notthe same as NUM_SECS_BW_SUM_INTERVAL. XXXX */ start += s_interval; @@ -1592,15 +1627,10 @@ rep_hist_load_bwhist_state_section(bw_array_t *b, }
/* Clean up maxima and observed */ - /* Do we really want to zero this for the purpose of max capacity? */ for (i=0; i<NUM_SECS_ROLLING_MEASURE; ++i) { b->obs[i] = 0; } b->total_obs = 0; - for (i=0; i<NUM_TOTALS; ++i) { - b->maxima[i] = 0; - } - b->max_total = 0;
return retval; } @@ -1619,6 +1649,7 @@ rep_hist_load_state(or_state_t *state, char **err) if (rep_hist_load_bwhist_state_section( \ (arrname), \ state->BWHistory ## st ## Values, \ + state->BWHistory ## st ## Maxima, \ state->BWHistory ## st ## Ends, \ state->BWHistory ## st ## Interval)<0) \ all_ok = 0