Jean-Marc Spaggiari created HBASE-18451:
-------------------------------------------
Summary: PeriodicMemstoreFlusher should inspect the queue before
adding a delayed flush request
Key: HBASE-18451
URL: https://issues.apache.org/jira/browse/HBASE-18451
Project: HBase
Issue Type: Bug
Components: regionserver
Affects Versions: 2.0.0-alpha-1
Reporter: Jean-Marc Spaggiari
If you run a big job every 4 hours, impacting many tables (they have 150
regions per server), ad the end all the regions might have some data to be
flushed, and we want, after one hour, trigger a periodic flush. That's totally
fine.
Now, to avoid a flush storm, when we detect a region to be flushed, we add a
"randomDelay" to the delayed flush, that way we spread them away.
RANGE_OF_DELAY is 5 minutes. So we spread the flush over the next 5 minutes,
which is very good.
However, because we don't check if there is already a request in the queue, 10
seconds after, we create a new request, with a new randomDelay.
If you generate a randomDelay every 10 seconds, at some point, you will end up
having a small one, and the flush will be triggered almost immediatly.
As a result, instead of spreading all the flush within the next 5 minutes, you
end-up getting them all way more quickly. Like within the first minute. Which
defeats the purpose of the randomDelay.
[code]
@Override
protected void chore() {
final StringBuffer whyFlush = new StringBuffer();
for (Region r : this.server.onlineRegions.values()) {
if (r == null) continue;
if (((HRegion)r).shouldFlush(whyFlush)) {
FlushRequester requester = server.getFlushRequester();
if (requester != null) {
long randomDelay = RandomUtils.nextInt(RANGE_OF_DELAY) +
MIN_DELAY_TIME;
LOG.info(getName() + " requesting flush of " +
r.getRegionInfo().getRegionNameAsString() + " because " +
whyFlush.toString() +
" after random delay " + randomDelay + "ms");
//Throttle the flushes by putting a delay. If we don't throttle,
and there
//is a balanced write-load on the regions in a table, we might end
up
//overwhelming the filesystem with too many flushes at once.
requester.requestDelayedFlush(r, randomDelay, false);
}
}
}
}
[code]
[code]
2017-07-24 18:44:33,338 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 270785ms
2017-07-24 18:44:43,328 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 200143ms
2017-07-24 18:44:53,954 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 191082ms
2017-07-24 18:45:03,528 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 92532ms
2017-07-24 18:45:14,201 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 238780ms
2017-07-24 18:45:24,195 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 35390ms
2017-07-24 18:45:33,362 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 283034ms
2017-07-24 18:45:43,933 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 84328ms
2017-07-24 18:45:53,866 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 72291ms
2017-07-24 18:46:03,329 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 62658ms
2017-07-24 18:46:14,084 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 87491ms
2017-07-24 18:46:23,538 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 290170ms
2017-07-24 18:46:33,353 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 228541ms
2017-07-24 18:46:43,359 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 211814ms
2017-07-24 18:46:54,150 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 155167ms
2017-07-24 18:47:03,546 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 115318ms
2017-07-24 18:47:13,350 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 216662ms
2017-07-24 18:47:23,329 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 96018ms
2017-07-24 18:47:33,891 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 144751ms
2017-07-24 18:47:43,329 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 152461ms
2017-07-24 18:47:53,832 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 97352ms
2017-07-24 18:48:03,348 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 263910ms
2017-07-24 18:48:13,353 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 151793ms
2017-07-24 18:48:23,340 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 61926ms
2017-07-24 18:48:33,724 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 188901ms
2017-07-24 18:48:44,038 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 233148ms
2017-07-24 18:48:53,624 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 6206ms
2017-07-24 18:49:03,378 INFO
org.apache.hadoop.hbase.regionserver.HRegionServer:
hbasetest2.domainname.com,60020,1500916375517-MemstoreFlusherChore requesting
flush of testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. because f
has an old edit so flush to free WALs after random delay 240946ms
2017-07-24 18:49:04,125 INFO org.apache.hadoop.hbase.regionserver.HRegion:
Flushing 1/1 column families, memstore=160 B
2017-07-24 18:49:04,182 INFO
org.apache.hadoop.hbase.regionserver.DefaultStoreFlusher: Flushed,
sequenceid=6, memsize=160, hasBloomFilter=true, into tmp file
hdfs://hbasetest1.domainname.com:8020/hbase/data/default/testflush/578c27d2eb7ef0ad437bf2ff38c053ae/.tmp/3609340d58ae4ca190e62c3b0fe415f4
2017-07-24 18:49:04,208 INFO org.apache.hadoop.hbase.regionserver.HStore: Added
hdfs://hbasetest1.domainname.com:8020/hbase/data/default/testflush/578c27d2eb7ef0ad437bf2ff38c053ae/f/3609340d58ae4ca190e62c3b0fe415f4,
entries=1, sequenceid=6, filesize=1015
2017-07-24 18:49:04,212 INFO org.apache.hadoop.hbase.regionserver.HRegion:
Finished memstore flush of ~160 B/160, currentsize=0 B/0 for region
testflush,,1500932649126.578c27d2eb7ef0ad437bf2ff38c053ae. in 87ms,
sequenceid=6, compaction requested=false
[code]
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
