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new 8afd129 [SYSTEMDS-2607,2608] Use relative timestamp for scoring
8afd129 is described below
commit 8afd129ca97e98cf7a9d10d3e624105c11c707a7
Author: arnabp <[email protected]>
AuthorDate: Mon Aug 10 19:47:53 2020 +0200
[SYSTEMDS-2607,2608] Use relative timestamp for scoring
This patch changes the following:
- use timestamp relative to execution start time instead of epoch
- remove SpilledItem class and related data structures
- re-reading of spilled items (no deletion from disk)
---
.../apache/sysds/runtime/lineage/LineageCache.java | 3 +-
.../sysds/runtime/lineage/LineageCacheConfig.java | 5 ++
.../sysds/runtime/lineage/LineageCacheEntry.java | 13 ++++-
.../runtime/lineage/LineageCacheEviction.java | 56 ++++++++++------------
4 files changed, 45 insertions(+), 32 deletions(-)
diff --git a/src/main/java/org/apache/sysds/runtime/lineage/LineageCache.java
b/src/main/java/org/apache/sysds/runtime/lineage/LineageCache.java
index be58d79..eef8bfb 100644
--- a/src/main/java/org/apache/sysds/runtime/lineage/LineageCache.java
+++ b/src/main/java/org/apache/sysds/runtime/lineage/LineageCache.java
@@ -62,6 +62,7 @@ public class LineageCache
static {
long maxMem = InfrastructureAnalyzer.getLocalMaxMemory();
LineageCacheEviction.setCacheLimit((long)(CACHE_FRAC * maxMem));
+ LineageCacheEviction.setStartTimestamp();
}
// Cache Synchronization Approach:
@@ -220,7 +221,7 @@ public class LineageCache
public static boolean probe(LineageItem key) {
//TODO problematic as after probe the matrix might be kicked
out of cache
- boolean p = (_cache.containsKey(key) ||
LineageCacheEviction.spillListContains(key));
+ boolean p = _cache.containsKey(key); // in cache or in disk
if (!p && DMLScript.STATISTICS &&
LineageCacheEviction._removelist.contains(key))
// The sought entry was in cache but removed later
LineageCacheStatistics.incrementDelHits();
diff --git
a/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheConfig.java
b/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheConfig.java
index f17e055..45fd34b 100644
--- a/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheConfig.java
+++ b/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheConfig.java
@@ -224,6 +224,11 @@ public class LineageCacheConfig
break;
case HYBRID:
WEIGHTS[0] = 1; WEIGHTS[1] = 0.0033;
+ // FIXME: Relative timestamp fix reduces the
absolute
+ // value of the timestamp component of the
scoring function
+ // to a comparatively much smaller number. W[1]
needs to be
+ // re-tuned accordingly.
+ // TODO: Automatic tuning of weights.
break;
}
_cachepolicy = policy;
diff --git
a/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheEntry.java
b/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheEntry.java
index 773dce6..983572c 100644
--- a/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheEntry.java
+++ b/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheEntry.java
@@ -35,6 +35,7 @@ public class LineageCacheEntry {
protected LineageCacheStatus _status;
protected LineageCacheEntry _nextEntry;
protected LineageItem _origItem;
+ private String _outfile = null;
protected double score;
public LineageCacheEntry(LineageItem key, DataType dt, MatrixBlock
Mval, ScalarObject Sval, long computetime) {
@@ -122,8 +123,18 @@ public class LineageCacheEntry {
_status = LineageCacheStatus.EMPTY;
}
+ protected synchronized void setOutfile(String outfile) {
+ _outfile = outfile;
+ }
+
+ protected synchronized String getOutfile() {
+ return _outfile;
+ }
+
protected synchronized void setTimestamp() {
- _timestamp = System.currentTimeMillis();
+ _timestamp = System.currentTimeMillis() -
LineageCacheEviction.getStartTimestamp();
+ if (_timestamp < 0)
+ throw new DMLRuntimeException ("Execution timestamp
shouldn't be -ve. Key: "+_key);
recomputeScore();
}
diff --git
a/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheEviction.java
b/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheEviction.java
index 43fa7c5..31fccc7 100644
--- a/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheEviction.java
+++ b/src/main/java/org/apache/sysds/runtime/lineage/LineageCacheEviction.java
@@ -20,7 +20,6 @@
package org.apache.sysds.runtime.lineage;
import java.io.IOException;
-import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
@@ -37,8 +36,8 @@ public class LineageCacheEviction
{
private static long _cachesize = 0;
private static long CACHE_LIMIT; //limit in bytes
+ private static long _startTimestamp = 0;
protected static final Set<LineageItem> _removelist = new HashSet<>();
- private static final Map<LineageItem, SpilledItem> _spillList = new
HashMap<>();
private static String _outdir = null;
private static TreeSet<LineageCacheEntry> weightedQueue = new
TreeSet<>(LineageCacheConfig.LineageCacheComparator);
@@ -46,7 +45,6 @@ public class LineageCacheEviction
// reset cache size, otherwise the cache clear leads to
unusable
// space which means evictions could run into endless loops
_cachesize = 0;
- _spillList.clear();
weightedQueue.clear();
_outdir = null;
if (DMLScript.STATISTICS)
@@ -240,6 +238,14 @@ public class LineageCacheEviction
//---------------- COSTING RELATED METHODS -----------------
+ protected static void setStartTimestamp() {
+ _startTimestamp = System.currentTimeMillis();
+ }
+
+ protected static long getStartTimestamp() {
+ return _startTimestamp;
+ }
+
private static double getDiskSpillEstimate(LineageCacheEntry e) {
if (!e.isMatrixValue() || e.isNullVal())
return 0;
@@ -299,6 +305,15 @@ public class LineageCacheEviction
if (entry.isNullVal())
throw new DMLRuntimeException ("Cannot spill null value
to disk. Key: "+entry._key);
+ // Do nothing if the entry is already spilled before.
+ if (entry._origItem == null && entry.getOutfile() != null)
+ return;
+ if (entry._origItem != null) {
+ LineageCacheEntry tmp = cache.get(entry._origItem);
//head
+ if (tmp.getOutfile() != null)
+ return;
+ }
+
long t0 = System.nanoTime();
if (_outdir == null) {
_outdir =
LocalFileUtils.getUniqueWorkingDir(LocalFileUtils.CATEGORY_LINEAGE);
@@ -316,12 +331,12 @@ public class LineageCacheEviction
// Add all the entries associated with this matrix to spillList.
if (entry._origItem == null) {
- _spillList.put(entry._key, new SpilledItem(outfile));
+ entry.setOutfile(outfile);
}
else {
LineageCacheEntry h = cache.get(entry._origItem); //head
while (h != null) {
- _spillList.put(h._key, new
SpilledItem(outfile));
+ h.setOutfile(outfile);
h = h._nextEntry;
}
}
@@ -336,19 +351,20 @@ public class LineageCacheEviction
if (cache.get(key) == null)
throw new DMLRuntimeException ("Spilled item should
present in cache. Key: "+key);
+ LineageCacheEntry e = cache.get(key);
long t0 = System.nanoTime();
MatrixBlock mb = null;
// Read from local FS
try {
- mb =
LocalFileUtils.readMatrixBlockFromLocal(_spillList.get(key)._outfile);
- } catch (IOException e) {
- throw new DMLRuntimeException ("Read from " +
_spillList.get(key)._outfile + " failed.", e);
+ mb =
LocalFileUtils.readMatrixBlockFromLocal(e.getOutfile());
+ } catch (IOException exp) {
+ throw new DMLRuntimeException ("Read from " +
e.getOutfile() + " failed.", exp);
}
- LocalFileUtils.deleteFileIfExists(_spillList.get(key)._outfile,
true);
+ // Keep the entry in disk to save re-spilling.
+
//LocalFileUtils.deleteFileIfExists(_spillList.get(key)._outfile, true);
long t1 = System.nanoTime();
// Restore to cache
- LineageCacheEntry e = cache.get(key);
e.setValue(mb);
if (e._origItem != null) {
// Restore to all the entries having the same data.
@@ -365,30 +381,10 @@ public class LineageCacheEviction
// Adjust disk reading speed
adjustReadWriteSpeed(e, ((double)(t1-t0))/1000000000, true);
// TODO: set cache status as RELOADED for this entry
- _spillList.remove(key);
if (DMLScript.STATISTICS) {
LineageCacheStatistics.incrementFSReadTime(t1-t0);
LineageCacheStatistics.incrementFSHits();
}
return cache.get(key);
}
-
- protected static boolean spillListContains(LineageItem key) {
- return _spillList.containsKey(key);
- }
-
- // ---------------- INTERNAL DATA STRUCTURES FOR EVICTION
-----------------
-
- // TODO: Remove this class, and add outfile to LineageCacheEntry.
- private static class SpilledItem {
- String _outfile;
- //long _computeTime;
- //protected LineageItem _origItem;
-
- public SpilledItem(String outfile) {
- _outfile = outfile;
- //_computeTime = computetime;
- //_origItem = origItem;
- }
- }
}
