WritePrepared: script to analyze stress test failures (#5033)

Summary:
This the hackish script we used to find the root cause of failures in transaction stress tests. It is not well-written and does not require rigorous reviewing but it is better than starting from scratch each time we observe an issue. The stress tests would just say that at which snapshots the sum of all the keys in a set is inconsistent with another set. To help debugging one need to know which key exactly returned inconsistent results. The script looks at the transactions between two conflicting snapshots, and performs thee changes manually to see for which key the read value was inconsistent.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5033

Differential Revision: D14280362

Pulled By: maysamyabandeh

fbshipit-source-id: d5826055c46711460ba81480d96cb5ea082814a5

tools/analyze_txn_stress_test.sh

@@ -0,0 +1,76 @@
+#!/bin/bash
+# Usage:
+# 1. Enable ROCKS_LOG_DETAILS in util/logging.h
+# 2. Run ./transaction_test --gtest_filter="MySQLStyleTransactionTest/MySQLStyleTransactionTest.TransactionStressTest/*" --gtest_break_on_failure
+# 3. SET=1 # 2 or 3
+# 4. LOG=/dev/shm/transaction_testdb_8600601584148590297/LOG
+# 5. grep RandomTransactionVerify $LOG | cut -d' ' -f 12 | sort -n # to find verify snapshots
+# 5. vn=1345
+# 6. vn_1=1340
+# 4. . tools/tools/analyze_txn_stress_test.sh
+echo Input params:
+# The rocksdb LOG path
+echo $LOG
+# Snapshot at which we got RandomTransactionVerify failure
+echo $vn
+# The snapshot before that where RandomTransactionVerify passed
+echo $vn_1
+# The stress tests use 3 sets, one or more might have shown inconsistent results.
+SET=${SET-1} # 1 or 2 or 3
+echo Checking set number $SET
+
+# Find the txns that committed between the two snapshots, and gather their changes made by them in /tmp/changes.txt
+# 2019/02/28-15:25:51.655477 7fffec9ff700 [DEBUG] [ilities/transactions/write_prepared_txn_db.cc:416] Txn 68497 Committing with 68498
+grep Committing $LOG | awk '{if ($9 <= vn && $9 > vn_1) print $0}' vn=$vn vn_1=${vn_1} > /tmp/txn.txt
+# 2019/02/28-15:25:49.046464 7fffe81f5700 [DEBUG] [il/transaction_test_util.cc:216] Commit of 65541 OK (txn12936193128775589751-9089)
+for i in `cat /tmp/txn.txt | awk '{print $6}'`; do grep "Commit of $i " $LOG; done > /tmp/names.txt
+for n in `cat /tmp/names.txt | awk '{print $9}'`; do grep $n $LOG; done > /tmp/changes.txt
+echo "Sum of the changes:"
+cat /tmp/changes.txt | grep Insert | awk '{print $12}' | cut -d= -f1 | cut -d+ -f2 | awk '{sum+=$1} END{print sum}'
+
+# Gather read values at each snapshot
+# 2019/02/28-15:25:51.655926 7fffebbff700 [DEBUG] [il/transaction_test_util.cc:347] VerifyRead at 67972 (67693): 000230 value: 15983
+grep "VerifyRead at ${vn_1} (.*): 000${SET}" $LOG | cut -d' ' -f 9- > /tmp/va.txt
+grep "VerifyRead at ${vn} (.*): 000${SET}" $LOG | cut -d' ' -f 9- > /tmp/vb.txt
+
+# For each key in the 2nd snapshot, find the value read by 1st, do the adds, and see if the results match.
+IFS=$'\n'
+for l in `cat /tmp/vb.txt`; 
+do
+  grep $l /tmp/va.txt > /dev/null ; 
+  if [[ $? -ne 0 ]]; then 
+    #echo $l
+    k=`echo $l | awk '{print $1}'`;
+    v=`echo $l | awk '{print $3}'`;
+    # 2019/02/28-15:25:19.350111 7fffe81f5700 [DEBUG] [il/transaction_test_util.cc:194] Insert (txn12936193128775589751-2298) OK snap: 16289 key:000219 value: 3772+95=3867
+    exp=`grep "\<$k\>" /tmp/changes.txt | tail -1 | cut -d= -f2`;
+    if [[ $v -ne $exp ]]; then echo $l; fi
+  else
+    k=`echo $l | awk '{print $1}'`;
+    grep "\<$k\>" /tmp/changes.txt
+  fi;
+done
+
+# Check that all the keys read in the 1st snapshot are still visible in the 2nd
+for l in `cat /tmp/va.txt`; 
+do
+  k=`echo $l | awk '{print $1}'`;
+  grep "\<$k\>" /tmp/vb.txt > /dev/null
+  if [[ $? -ne 0 ]]; then
+    echo missing key $k
+  fi
+done
+
+# The following found a bug in ValidateSnapshot. It checks if the adds on each key match up.
+grep Insert /tmp/changes.txt | cut -d' ' -f 10 | sort | uniq > /tmp/keys.txt
+for k in `cat /tmp/keys.txt`;
+do
+  grep "\<$k\>" /tmp/changes.txt > /tmp/adds.txt;
+  # 2019/02/28-15:25:19.350111 7fffe81f5700 [DEBUG] [il/transaction_test_util.cc:194] Insert (txn12936193128775589751-2298) OK snap: 16289 key:000219 value: 3772+95=3867
+  START=`head -1 /tmp/adds.txt | cut -d' ' -f 12 | cut -d+ -f1`
+  END=`tail -1 /tmp/adds.txt | cut -d' ' -f 12 | cut -d= -f2`
+  ADDS=`cat /tmp/adds.txt | grep Insert | awk '{print $12}' | cut -d= -f1 | cut -d+ -f2 | awk '{sum+=$1} END{print sum}'`
+  EXP=$((START+ADDS))
+  # If first + all the adds != last then there was an issue with ValidateSnapshot.
+  if [[ $END -ne $EXP ]]; then echo inconsistent txn: $k $START+$ADDS=$END; cat /tmp/adds.txt; return 1; fi
+done