// . but now that we may get a list remotely to fix data corruption,
// this may indeed block
bool Msg3::doneScanning ( ) {
QUICKPOLL(m_niceness);
// . did we have any error on any scan?
// . if so, repeat ALL of the scans
g_errno = m_errno;
// 2 retry is the default
int32_t max = 2;
// see if explicitly provided by the caller
if ( m_maxRetries >= 0 ) max = m_maxRetries;
// now use -1 (no max) as the default no matter what
max = -1;
// ENOMEM is particulary contagious, so watch out with it...
if ( g_errno == ENOMEM && m_maxRetries == -1 ) max = 0;
// msg0 sets maxRetries to 2, don't let max stay set to -1
if ( g_errno == ENOMEM && m_maxRetries != -1 ) max = m_maxRetries;
// when thread cannot alloc enough read buf it keeps the read buf
// set to NULL and BigFile.cpp sets g_errno to EBUFTOOSMALL
if ( g_errno == EBUFTOOSMALL && m_maxRetries == -1 ) max = 0;
// msg0 sets maxRetries to 2, don't let max stay set to -1
if ( g_errno == EBUFTOOSMALL && m_maxRetries != -1 ) max = m_maxRetries;
// . if no thread slots available, that hogs up serious memory.
// the size of Msg3 is 82k, so having just 5000 of them is 430MB.
// . i just made Msg3 alloc mem when it needs more than about 2k
// so this problem is greatly reduced, therefore let's keep
// retrying... forever if no thread slots in thread queue since
// we become the thread queue in a way.
if ( g_errno == ENOTHREADSLOTS ) max = -1;
// this is set above if the map has the same consecutive key repeated
// and the read is enormous
if ( g_errno == ECORRUPTDATA ) max = 0;
// usually bad disk failures, don't retry those forever
//if ( g_errno == EIO ) max = 3;
// no, now our hitachis return these even when they're good so
// we have to keep retrying forever
if ( g_errno == EIO ) max = -1;
// count these so we do not take drives offline just because
// kernel ring buffer complains...
if ( g_errno == EIO ) g_numIOErrors++;
// bail early on high priority reads for these errors
if ( g_errno == EDISKSTUCK && m_niceness == 0 ) max = 0;
if ( g_errno == EIO && m_niceness == 0 ) max = 0;
// how does this happen? we should never bail out on a low priority
// disk read... we just wait for it to complete...
if ( g_errno == EDISKSTUCK && m_niceness != 0 ) { char *xx=NULL;*xx=0;}
// on I/O, give up at call it corrupt after a while. some hitachis
// have I/O errros on little spots, like gk88, maybe we can fix him
if ( g_errno == EIO && m_retryNum >= 5 ) {
m_errno = ECORRUPTDATA;
m_hadCorruption = true;
// do not do any retries any more
max = 0;
}
// convert m_errno to ECORRUPTDATA if it is EBUFTOOSMALL and the
// max of the bytesToRead are over 500MB.
// if bytesToRead was ludicrous, then assume that the data file
// was corrupted, the map was regenerated and it patched
// over the corrupted bits which were 500MB or more in size.
// we cannot practically allocate that much, so let's just
// give back an empty buffer. treat it like corruption...
// the way it patches is to store the same key over all the corrupted
// pages, which can get pretty big. so if you read a range with that
// key you will be hurting!!
// this may be the same scenario as when the rdbmap has consecutive
// same keys. see above where we set m_errno to ECORRUPTDATA...
if ( g_errno == EBUFTOOSMALL ) {
int32_t biggest = 0;
for ( int32_t i = 0 ; i < m_numFileNums ; i++ ) {
if ( m_scans[i].m_bytesToRead < biggest ) continue;
biggest = m_scans[i].m_bytesToRead;
}
if ( biggest > 500000000 ) {
log("db: Max read size was %" PRId32" > 500000000. Assuming "
"corrupt data in data file.",biggest);
m_errno = ECORRUPTDATA;
m_hadCorruption = true;
// do not do any retries on this, the read was > 500MB
max = 0;
}
}
// if shutting down gb then limit to 20 so we can shutdown because
// it can't shutdown until all threads are out of the queue i think
if ( g_process.m_mode == EXIT_MODE && max < 0 ) {
//log("msg3: forcing retries to 0 because shutting down");
max = 0;
}
// get base, returns NULL and sets g_errno to ENOCOLLREC on error
RdbBase *base = getRdbBase( m_rdbId, m_collnum );
if ( ! base ) {
return true;
}
// this really slows things down because it blocks the cpu so
// leave it out for now
#ifdef GBSANITYCHECK
// check for corruption here, do not do it again in Msg5 if we pass
if ( ! g_errno ) { // && g_conf.m_doErrorCorrection ) {
int32_t i;
for ( i = 0 ; i < m_numFileNums ; i++ )
if ( ! m_lists[i].checkList_r ( false, false ) ) break;
if ( i < m_numFileNums ) {
g_errno = ECORRUPTDATA;
m_errno = ECORRUPTDATA;
max = g_conf.m_corruptRetries; // try 100 times
log("db: Encountered corrupt list in file %s.",
base->getFile(m_fileNums[i])->getFilename());
}
else
m_listsChecked = true;
}
#endif
// try to fix this error i've seen
if ( g_errno == EBADENGINEER && max == -1 )
max = 100;
// . if we had a ETRYAGAIN error, then try again now
// . it usually means the whole file or a part of it was deleted
// before we could finish reading it, so we should re-read all now
// . RdbMerge deletes BigFiles after it merges them and also chops
// off file heads
// . now that we have threads i'd imagine we'd get EBADFD or something
// . i've also seen "illegal seek" as well
if ( m_errno && (m_retryNum < max || max < 0) &&
// this will complete in due time, we can't call a sleep wrapper
// on it because the read is really still pending...
m_errno != EDISKSTUCK ) {
// print the error
static time_t s_time = 0;
time_t now = getTime();
if ( now - s_time > 5 || g_errno != ENOTHREADSLOTS ) {
log("net: Had error reading %s: %s. Retrying. "
"(retry #%" PRId32")",
base->m_dbname,mstrerror(m_errno) , m_retryNum );
s_time = now;
}
// send email alert if in an infinite loop, but don't send
// more than once every 2 hours
static int32_t s_lastSendTime = 0;
if ( m_retryNum == 100 && getTime() - s_lastSendTime > 3600*2){
// remove this for now it is going off all the time
//g_pingServer.sendEmail(NULL,//g_hostdb.getMyHost(),
// "100 read retries",true);
s_lastSendTime = getTime();
}
// clear g_errno cuz we should for call to readList()
g_errno = 0;
// free the list buffer since if we have 1000 Msg3s retrying
// it will totally use all of our memory
for ( int32_t i = 0 ; i < m_numChunks ; i++ )
m_lists[i].destructor();
// count retries
m_retryNum++;
// backoff scheme, wait 100ms more each time
int32_t wait ;
if ( m_retryNum == 1 ) wait = 10;
else wait = 200 * m_retryNum;
// . don't wait more than 10 secs between tries
// . i've seen gf0 and gf16 get mega saturated
if ( wait > 10000 ) wait = 10000;
// wait 500 ms
if ( g_loop.registerSleepCallback ( wait , // ms
this ,
doneSleepingWrapper3,
m_niceness))
return false;
// otherwise, registration failed
log(
"net: Failed to register sleep callback for retry. "
"Abandoning read. This is bad.");
// return, g_errno should be set
g_errno = EBUFTOOSMALL;
m_errno = EBUFTOOSMALL;
return true;
}
// if we got an error and should not retry any more then give up
if ( g_errno ) {
log(
"net: Had error reading %s: %s. Giving up after %" PRId32" "
"retries.",
base->m_dbname,mstrerror(g_errno) , m_retryNum );
return true;
}
// note it if the retry finally worked
if ( m_retryNum > 0 )
log(LOG_INFO,"disk: Read succeeded after retrying %" PRId32" times.",
(int32_t)m_retryNum);
// count total bytes for logging
int32_t count = 0;
// . constrain all lists to make merging easier
// . if we have only one list, then that's nice cuz the constrain
// will allow us to send it right away w/ zero copying
// . if we have only 1 list, it won't be merged into a final list,
// that is, we'll just set m_list = &m_lists[i]
for ( int32_t i = 0 ; i < m_numFileNums ; i++ ) {
QUICKPOLL(m_niceness);
// count total bytes for logging
count += m_lists[i].getListSize();
// . hint offset is relative to the offset of first key we read
// . if that key was only 6 bytes RdbScan shift the list buf
// down 6 bytes to make the first key 12 bytes... a
// requirement for all RdbLists
// . don't inc it, though, if it was 0, pointing to the start
// of the list because our shift won't affect that
if ( m_scans[i].m_shifted == 6 && m_hintOffsets[i] > 0 )
m_hintOffsets[i] += 6;
// posdb double compression
if ( m_scans[i].m_shifted == 12 && m_hintOffsets[i] > 0 )
m_hintOffsets[i] += 12;
// . don't constrain on minRecSizes here because it may
// make our endKey smaller, which will cause problems
// when Msg5 merges these lists.
// . If all lists have different endKeys RdbList's merge
// chooses the min and will merge in recs beyond that
// causing a bad list BECAUSE we don't check to make
// sure that recs we are adding are below the endKey
// . if we only read from one file then constrain based
// on minRecSizes so we can send the list back w/o merging
// OR if just merging with RdbTree's list
int32_t mrs ;
// . constrain to m_minRecSizesOrig, not m_minRecSizes cuz
// that could be adjusted by compensateForNegativeRecs()
// . but, really, they should be the same if we only read from
// the root file
if ( m_numFileNums == 1 ) mrs = m_minRecSizesOrig;
else mrs = -1;
// . this returns false and sets g_errno on error
// . like if data is corrupt
BigFile *ff = base->getFile(m_fileNums[i]);
// if we did a merge really quick and delete one of the
// files we were reading, i've seen 'ff' be NULL
char *filename = "lostfilename";
if ( ff ) filename = ff->getFilename();
// compute cache info
RdbCache *rpc = getDiskPageCache ( m_rdbId );
if ( ! m_allowPageCache ) rpc = NULL;
int64_t vfd ;
if ( ff ) vfd = ff->getVfd();
key192_t ck ;
if ( ff )
ck = makeCacheKey ( vfd ,
m_scans[i].m_offset ,
m_scans[i].m_bytesToRead );
if ( m_validateCache && ff && rpc && vfd != -1 ) {
bool inCache;
char *rec; int32_t recSize;
inCache = rpc->getRecord ( (collnum_t)0 , // collnum
(char *)&ck ,
&rec ,
&recSize ,
true , // copy?
-1 , // maxAge, none
true ); // inccounts?
if ( inCache &&
// 1st byte is RdbScan::m_shifted
( m_lists[i].m_listSize != recSize-1 ||
memcmp ( m_lists[i].m_list , rec+1,recSize-1) ||
*rec != m_scans[i].m_shifted ) ) {
log("msg3: cache did not validate");
char *xx=NULL;*xx=0;
}
mfree ( rec , recSize , "vca" );
}
///////
//
// STORE IN PAGE CACHE
//
///////
// store what we read in the cache. don't bother storing
// if it was a retry, just in case something strange happened.
// store pre-constrain call is more efficient.
if ( m_retryNum<=0 && ff && rpc && vfd != -1 &&
! m_scans[i].m_inPageCache )
rpc->addRecord ( (collnum_t)0 , // collnum
(char *)&ck ,
// rec1 is this little thingy
&m_scans[i].m_shifted,
1,
// rec2
m_lists[i].getList() ,
m_lists[i].getListSize() ,
0 ); // timestamp. 0 = now
QUICKPOLL(m_niceness);
// if from our 'page' cache, no need to constrain
if ( ! m_lists[i].constrain ( m_startKey ,
m_constrainKey , // m_endKey
mrs , // m_minRecSizes
m_hintOffsets[i] ,
//m_hintKeys [i] ,
&m_hintKeys [i*m_ks] ,
filename,//ff->getFilename() ,
m_niceness ) ) {
log("net: Had error while constraining list read from "
"%s: %s/%s. vfd=%" PRId32" parts=%" PRId32". "
"This is likely caused by corrupted "
"data on disk.",
mstrerror(g_errno), ff->getDir(),
ff->getFilename(), ff->m_vfd ,
(int32_t)ff->m_numParts );
continue;
}
}
// print the time
if ( g_conf.m_logTimingDb ) {
int64_t now = gettimeofdayInMilliseconds();
int64_t took = now - m_startTime;
log(LOG_TIMING,
"net: Took %" PRId64" ms to read %" PRId32" lists of %" PRId32" bytes total"
" from %s (niceness=%" PRId32").",
took,m_numFileNums,count,base->m_dbname,m_niceness);
}
return true;
}
// . sets m_errno to g_errno if not already set
void Msg51::gotClusterRec(Slot *slot) {
// count it
m_numReplies++;
// free up
slot->m_inUse = false;
RdbList *list = slot->m_msg0.m_list;
// update m_errno if we had an error
if ( ! m_errno ) m_errno = g_errno;
if ( g_errno )
// print error
log(LOG_DEBUG,
"query: Had error getting cluster info got docId=d: "
"%s.",mstrerror(g_errno));
// this doubles as a ptr to a cluster rec
int32_t ci = slot->m_ci;
// get docid
int64_t docId = m_docIds[ci];
// assume error!
m_clusterLevels[ci] = CR_ERROR_CLUSTERDB;
// bail on error
if ( g_errno || list->getListSize() < 12 ) {
//log(LOG_DEBUG,
// "build: clusterdb rec for d=%" PRId64" dptr=%" PRIu32" "
// "not found. where is it?", docId, (int32_t)ci);
g_errno = 0;
return;
}
// . steal rec from this multicast
// . point to cluster rec, a int32_t
key96_t *rec = &m_clusterRecs[ci];
// store the cluster rec itself
*rec = *(key96_t *)(list->getList());
// debug note
log(LOG_DEBUG,
"build: had clusterdb SUCCESS for d=%" PRId64" dptr=%" PRIu32" "
"rec.n1=%" PRIx32",%016" PRIx64" sitehash26=0x%" PRIx32".", (int64_t)docId, (int32_t)ci,
rec->n1,rec->n0,
g_clusterdb.getSiteHash26((char *)rec));
// check for docid mismatch
int64_t docId2 = g_clusterdb.getDocId ( rec );
if ( docId != docId2 ) {
logf(LOG_DEBUG,"query: docid mismatch in clusterdb.");
return;
}
// it is legit, set to CR_OK
m_clusterLevels[ci] = CR_OK;
// . init the quick cache
// . use 100k
if ( ! s_cacheInit &&
s_clusterdbQuickCache.init(200*1024 , // maxMem
sizeof(key96_t) , // fixedDataSize (clusterdb rec)
false , // support lists
10000 , // max recs
false , // use half keys?
"clusterdbQuickCache" ,
false , // load from disk?
sizeof(key96_t) , // cache key size
sizeof(key96_t) )) // cache key size
// only init once if successful
s_cacheInit = true;
// debug msg
//logf(LOG_DEBUG,"query: msg51 addRec k.n0=%" PRIu64" rec.n0=%" PRIu64,docId,
// rec->n0);
// . add the record to our quick cache as a int64_t
// . ignore any error
if ( s_cacheInit )
s_clusterdbQuickCache.addRecord(m_collnum,
(key96_t)docId, // docid is key
(char *)rec,
sizeof(key96_t), // recSize
0);
// clear it in case the cache set it, we don't care
g_errno = 0;
}
