From ae22d84ef0d00c3cca010633cf9949f0fdc2dba8 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Wed, 5 Aug 2020 12:23:41 +0300
Subject: [PATCH 01/17] v1.1.0

---
 RELEASE_VERSION | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/RELEASE_VERSION b/RELEASE_VERSION
index f1339850d..9084fa2f7 100644
--- a/RELEASE_VERSION
+++ b/RELEASE_VERSION
@@ -1 +1 @@
-1.0.49
+1.1.0

From 294d43b4f6455bc3dcaf0c88d025778d1e958ca0 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 31 Dec 2020 09:29:38 +0200
Subject: [PATCH 02/17] WIP: copying AUTO_INCREMENT value to ghost table
 Initial commit: towards setting up a test suite

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 localtests/test.sh | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/localtests/test.sh b/localtests/test.sh
index d4b3f1723..05762c288 100755
--- a/localtests/test.sh
+++ b/localtests/test.sh
@@ -12,6 +12,7 @@ test_logfile=/tmp/gh-ost-test.log
 default_ghost_binary=/tmp/gh-ost-test
 ghost_binary=""
 exec_command_file=/tmp/gh-ost-test.bash
+ghost_structure_output_file=/tmp/gh-ost-test.ghost.structure.sql
 orig_content_output_file=/tmp/gh-ost-test.orig.content.csv
 ghost_content_output_file=/tmp/gh-ost-test.ghost.content.csv
 throttle_flag_file=/tmp/gh-ost-test.ghost.throttle.flag
@@ -204,6 +205,18 @@ test_single() {
     return 1
   fi
 
+  gh-ost-test-mysql-replica --default-character-set=utf8mb4 test -e "show create table _gh_ost_test_gho\G" -ss > $ghost_structure_output_file
+
+  # if [ -f $tests_path/$test_name/expect_table_structure ] ; then
+  #   expected_table_structure="$(cat $tests_path/$test_name/expect_table_structure)"
+  #   if grep -q "$expected_table_structure" $test_logfile ; then
+  #       return 0
+  #   fi
+  #   echo
+  #   echo "ERROR $test_name execution was expected to exit with error message '${expected_error_message}' but did not. cat $test_logfile"
+  #   return 1
+  # fi
+
   echo_dot
   gh-ost-test-mysql-replica --default-character-set=utf8mb4 test -e "select ${orig_columns} from gh_ost_test ${order_by}" -ss > $orig_content_output_file
   gh-ost-test-mysql-replica --default-character-set=utf8mb4 test -e "select ${ghost_columns} from _gh_ost_test_gho ${order_by}" -ss > $ghost_content_output_file

From 26f76027b2806ad2885c465c0f02bcd1c69bb3f8 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 31 Dec 2020 09:48:08 +0200
Subject: [PATCH 03/17] greping for 'expect_table_structure' content

---
 localtests/test.sh | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/localtests/test.sh b/localtests/test.sh
index 05762c288..eb3d6403b 100755
--- a/localtests/test.sh
+++ b/localtests/test.sh
@@ -207,15 +207,15 @@ test_single() {
 
   gh-ost-test-mysql-replica --default-character-set=utf8mb4 test -e "show create table _gh_ost_test_gho\G" -ss > $ghost_structure_output_file
 
-  # if [ -f $tests_path/$test_name/expect_table_structure ] ; then
-  #   expected_table_structure="$(cat $tests_path/$test_name/expect_table_structure)"
-  #   if grep -q "$expected_table_structure" $test_logfile ; then
-  #       return 0
-  #   fi
-  #   echo
-  #   echo "ERROR $test_name execution was expected to exit with error message '${expected_error_message}' but did not. cat $test_logfile"
-  #   return 1
-  # fi
+  if [ -f $tests_path/$test_name/expect_table_structure ] ; then
+    expected_table_structure="$(cat $tests_path/$test_name/expect_table_structure)"
+    if ! grep -q "$expected_table_structure" $ghost_structure_output_file ; then
+      echo
+      echo "ERROR $test_name: table structure was expected to include ${expected_table_structure} but did not. cat $ghost_structure_output_file:"
+      cat $ghost_structure_output_file
+      return 1
+    fi
+  fi
 
   echo_dot
   gh-ost-test-mysql-replica --default-character-set=utf8mb4 test -e "select ${orig_columns} from gh_ost_test ${order_by}" -ss > $orig_content_output_file

From 75009db84911867a3fc37b3d2efcf442064e5753 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 31 Dec 2020 09:50:56 +0200
Subject: [PATCH 04/17] Adding simple test for 'expect_table_structure'
 scenario

---
 localtests/autoinc-copy-simple/create.sql             | 11 +++++++++++
 localtests/autoinc-copy-simple/expect_table_structure |  1 +
 2 files changed, 12 insertions(+)
 create mode 100644 localtests/autoinc-copy-simple/create.sql
 create mode 100644 localtests/autoinc-copy-simple/expect_table_structure

diff --git a/localtests/autoinc-copy-simple/create.sql b/localtests/autoinc-copy-simple/create.sql
new file mode 100644
index 000000000..8aa19bba3
--- /dev/null
+++ b/localtests/autoinc-copy-simple/create.sql
@@ -0,0 +1,11 @@
+drop table if exists gh_ost_test;
+create table gh_ost_test (
+  id int auto_increment,
+  i int not null,
+  primary key(id)
+) auto_increment=1;
+
+insert into gh_ost_test values (NULL, 11);
+insert into gh_ost_test values (NULL, 13);
+insert into gh_ost_test values (NULL, 17);
+insert into gh_ost_test values (NULL, 23);
diff --git a/localtests/autoinc-copy-simple/expect_table_structure b/localtests/autoinc-copy-simple/expect_table_structure
new file mode 100644
index 000000000..3ed59021b
--- /dev/null
+++ b/localtests/autoinc-copy-simple/expect_table_structure
@@ -0,0 +1 @@
+AUTO_INCREMENT=5

From eeab264eb2436fc0741a7f0626b1fd8a1b80061d Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 31 Dec 2020 09:53:37 +0200
Subject: [PATCH 05/17] adding tests for AUTO_INCREMENT value after row
 deletes. Should initially fail

---
 localtests/autoinc-copy-deletes/create.sql        | 15 +++++++++++++++
 .../autoinc-copy-deletes/expect_table_structure   |  1 +
 2 files changed, 16 insertions(+)
 create mode 100644 localtests/autoinc-copy-deletes/create.sql
 create mode 100644 localtests/autoinc-copy-deletes/expect_table_structure

diff --git a/localtests/autoinc-copy-deletes/create.sql b/localtests/autoinc-copy-deletes/create.sql
new file mode 100644
index 000000000..dde7f0978
--- /dev/null
+++ b/localtests/autoinc-copy-deletes/create.sql
@@ -0,0 +1,15 @@
+drop table if exists gh_ost_test;
+create table gh_ost_test (
+  id int auto_increment,
+  i int not null,
+  primary key(id)
+) auto_increment=1;
+
+insert into gh_ost_test values (NULL, 11);
+insert into gh_ost_test values (NULL, 13);
+insert into gh_ost_test values (NULL, 17);
+insert into gh_ost_test values (NULL, 23);
+insert into gh_ost_test values (NULL, 29);
+insert into gh_ost_test values (NULL, 31);
+insert into gh_ost_test values (NULL, 37);
+delete from gh_ost_test where id>5;
diff --git a/localtests/autoinc-copy-deletes/expect_table_structure b/localtests/autoinc-copy-deletes/expect_table_structure
new file mode 100644
index 000000000..5a755ffb8
--- /dev/null
+++ b/localtests/autoinc-copy-deletes/expect_table_structure
@@ -0,0 +1 @@
+AUTO_INCREMENT=8

From 2d0281f29b267739b337c28c4738736d9759054d Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 31 Dec 2020 10:06:12 +0200
Subject: [PATCH 06/17] clear event beforehand

---
 localtests/autoinc-copy-deletes/create.sql | 2 ++
 localtests/autoinc-copy-simple/create.sql  | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/localtests/autoinc-copy-deletes/create.sql b/localtests/autoinc-copy-deletes/create.sql
index dde7f0978..0d668128d 100644
--- a/localtests/autoinc-copy-deletes/create.sql
+++ b/localtests/autoinc-copy-deletes/create.sql
@@ -1,3 +1,5 @@
+drop event if exists gh_ost_test;
+
 drop table if exists gh_ost_test;
 create table gh_ost_test (
   id int auto_increment,
diff --git a/localtests/autoinc-copy-simple/create.sql b/localtests/autoinc-copy-simple/create.sql
index 8aa19bba3..677f08e4c 100644
--- a/localtests/autoinc-copy-simple/create.sql
+++ b/localtests/autoinc-copy-simple/create.sql
@@ -1,3 +1,5 @@
+drop event if exists gh_ost_test;
+
 drop table if exists gh_ost_test;
 create table gh_ost_test (
   id int auto_increment,

From af20211629c9a47631749ebb5359ec1c08c3d0a1 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 31 Dec 2020 11:01:13 +0200
Subject: [PATCH 07/17] parsing AUTO_INCREMENT from alter query, reading
 AUTO_INCREMENT from original table, applying AUTO_INCREMENT value onto ghost
 table if applicable and user has not specified AUTO_INCREMENT in alter
 statement

---
 go/base/context.go    |  1 +
 go/logic/applier.go   | 19 +++++++++++++++++++
 go/logic/inspect.go   | 22 ++++++++++++++++++++++
 go/logic/migrator.go  |  8 ++++++++
 go/sql/parser.go      | 19 ++++++++++++++++---
 go/sql/parser_test.go | 24 ++++++++++++++++++++++++
 6 files changed, 90 insertions(+), 3 deletions(-)

diff --git a/go/base/context.go b/go/base/context.go
index cee66efe7..5419d5742 100644
--- a/go/base/context.go
+++ b/go/base/context.go
@@ -203,6 +203,7 @@ type MigrationContext struct {
 	OriginalTableColumns             *sql.ColumnList
 	OriginalTableVirtualColumns      *sql.ColumnList
 	OriginalTableUniqueKeys          [](*sql.UniqueKey)
+	OriginalTableAutoIncrement       uint64
 	GhostTableColumns                *sql.ColumnList
 	GhostTableVirtualColumns         *sql.ColumnList
 	GhostTableUniqueKeys             [](*sql.UniqueKey)
diff --git a/go/logic/applier.go b/go/logic/applier.go
index 089978c25..cc0aa01a3 100644
--- a/go/logic/applier.go
+++ b/go/logic/applier.go
@@ -204,6 +204,25 @@ func (this *Applier) AlterGhost() error {
 	return nil
 }
 
+// AlterGhost applies `alter` statement on ghost table
+func (this *Applier) AlterGhostAutoIncrement() error {
+	query := fmt.Sprintf(`alter /* gh-ost */ table %s.%s AUTO_INCREMENT=%d`,
+		sql.EscapeName(this.migrationContext.DatabaseName),
+		sql.EscapeName(this.migrationContext.GetGhostTableName()),
+		this.migrationContext.OriginalTableAutoIncrement,
+	)
+	this.migrationContext.Log.Infof("Altering ghost table AUTO_INCREMENT value %s.%s",
+		sql.EscapeName(this.migrationContext.DatabaseName),
+		sql.EscapeName(this.migrationContext.GetGhostTableName()),
+	)
+	this.migrationContext.Log.Debugf("AUTO_INCREMENT ALTER statement: %s", query)
+	if _, err := sqlutils.ExecNoPrepare(this.db, query); err != nil {
+		return err
+	}
+	this.migrationContext.Log.Infof("Ghost table AUTO_INCREMENT altered")
+	return nil
+}
+
 // CreateChangelogTable creates the changelog table on the applier host
 func (this *Applier) CreateChangelogTable() error {
 	if err := this.DropChangelogTable(); err != nil {
diff --git a/go/logic/inspect.go b/go/logic/inspect.go
index bc1083061..23f238ae6 100644
--- a/go/logic/inspect.go
+++ b/go/logic/inspect.go
@@ -109,6 +109,10 @@ func (this *Inspector) InspectOriginalTable() (err error) {
 	if err != nil {
 		return err
 	}
+	this.migrationContext.OriginalTableAutoIncrement, err = this.getAutoIncrementValue(this.migrationContext.OriginalTableName)
+	if err != nil {
+		return err
+	}
 	return nil
 }
 
@@ -589,6 +593,24 @@ func (this *Inspector) applyColumnTypes(databaseName, tableName string, columnsL
 	return err
 }
 
+// getAutoIncrementValue get's the original table's AUTO_INCREMENT value, if exists (0 value if not exists)
+func (this *Inspector) getAutoIncrementValue(tableName string) (autoIncrement uint64, err error) {
+	query := `
+    SELECT
+			AUTO_INCREMENT
+    FROM INFORMATION_SCHEMA.TABLES
+    WHERE
+			TABLES.TABLE_SCHEMA = ?
+			AND TABLES.TABLE_NAME = ?
+			AND AUTO_INCREMENT IS NOT NULL
+  `
+	err = sqlutils.QueryRowsMap(this.db, query, func(m sqlutils.RowMap) error {
+		autoIncrement = m.GetUint64("AUTO_INCREMENT")
+		return nil
+	}, this.migrationContext.DatabaseName, tableName)
+	return autoIncrement, err
+}
+
 // getCandidateUniqueKeys investigates a table and returns the list of unique keys
 // candidate for chunking
 func (this *Inspector) getCandidateUniqueKeys(tableName string) (uniqueKeys [](*sql.UniqueKey), err error) {
diff --git a/go/logic/migrator.go b/go/logic/migrator.go
index 70af08db9..10df55581 100644
--- a/go/logic/migrator.go
+++ b/go/logic/migrator.go
@@ -1068,6 +1068,14 @@ func (this *Migrator) initiateApplier() error {
 		return err
 	}
 
+	if this.migrationContext.OriginalTableAutoIncrement > 0 && !this.parser.IsAutoIncrementDefined() {
+		// Original table has AUTO_INCREMENT value and the -alter statement does not indicate any override,
+		// so we should copy AUTO_INCREMENT value onto our ghost table.
+		if err := this.applier.AlterGhostAutoIncrement(); err != nil {
+			this.migrationContext.Log.Errorf("Unable to ALTER ghost table AUTO_INCREMENT value, see further error details. Bailing out")
+			return err
+		}
+	}
 	this.applier.WriteChangelogState(string(GhostTableMigrated))
 	go this.applier.InitiateHeartbeat()
 	return nil
diff --git a/go/sql/parser.go b/go/sql/parser.go
index ebb8b3883..d9c0c3f19 100644
--- a/go/sql/parser.go
+++ b/go/sql/parser.go
@@ -16,6 +16,7 @@ var (
 	renameColumnRegexp                   = regexp.MustCompile(`(?i)\bchange\s+(column\s+|)([\S]+)\s+([\S]+)\s+`)
 	dropColumnRegexp                     = regexp.MustCompile(`(?i)\bdrop\s+(column\s+|)([\S]+)$`)
 	renameTableRegexp                    = regexp.MustCompile(`(?i)\brename\s+(to|as)\s+`)
+	autoIncrementRegexp                  = regexp.MustCompile(`(?i)\bauto_increment[\s]*=[\s]*([0-9]+)`)
 	alterTableExplicitSchemaTableRegexps = []*regexp.Regexp{
 		// ALTER TABLE `scm`.`tbl` something
 		regexp.MustCompile(`(?i)\balter\s+table\s+` + "`" + `([^` + "`" + `]+)` + "`" + `[.]` + "`" + `([^` + "`" + `]+)` + "`" + `\s+(.*$)`),
@@ -35,9 +36,10 @@ var (
 )
 
 type AlterTableParser struct {
-	columnRenameMap map[string]string
-	droppedColumns  map[string]bool
-	isRenameTable   bool
+	columnRenameMap        map[string]string
+	droppedColumns         map[string]bool
+	isRenameTable          bool
+	isAutoIncrementDefined bool
 
 	alterStatementOptions string
 	alterTokens           []string
@@ -122,6 +124,12 @@ func (this *AlterTableParser) parseAlterToken(alterToken string) (err error) {
 			this.isRenameTable = true
 		}
 	}
+	{
+		// auto_increment
+		if autoIncrementRegexp.MatchString(alterToken) {
+			this.isAutoIncrementDefined = true
+		}
+	}
 	return nil
 }
 
@@ -173,6 +181,11 @@ func (this *AlterTableParser) DroppedColumnsMap() map[string]bool {
 func (this *AlterTableParser) IsRenameTable() bool {
 	return this.isRenameTable
 }
+
+func (this *AlterTableParser) IsAutoIncrementDefined() bool {
+	return this.isAutoIncrementDefined
+}
+
 func (this *AlterTableParser) GetExplicitSchema() string {
 	return this.explicitSchema
 }
diff --git a/go/sql/parser_test.go b/go/sql/parser_test.go
index 79faa630e..6cdbb39cc 100644
--- a/go/sql/parser_test.go
+++ b/go/sql/parser_test.go
@@ -24,6 +24,7 @@ func TestParseAlterStatement(t *testing.T) {
 	test.S(t).ExpectNil(err)
 	test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
 	test.S(t).ExpectFalse(parser.HasNonTrivialRenames())
+	test.S(t).ExpectFalse(parser.IsAutoIncrementDefined())
 }
 
 func TestParseAlterStatementTrivialRename(t *testing.T) {
@@ -33,10 +34,31 @@ func TestParseAlterStatementTrivialRename(t *testing.T) {
 	test.S(t).ExpectNil(err)
 	test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
 	test.S(t).ExpectFalse(parser.HasNonTrivialRenames())
+	test.S(t).ExpectFalse(parser.IsAutoIncrementDefined())
 	test.S(t).ExpectEquals(len(parser.columnRenameMap), 1)
 	test.S(t).ExpectEquals(parser.columnRenameMap["ts"], "ts")
 }
 
+func TestParseAlterStatementWithAutoIncrement(t *testing.T) {
+
+	statements := []string{
+		"auto_increment=7",
+		"auto_increment = 7",
+		"AUTO_INCREMENT = 71",
+		"add column t int, change ts ts timestamp, auto_increment=7 engine=innodb",
+		"add column t int, change ts ts timestamp, auto_increment =7 engine=innodb",
+		"add column t int, change ts ts timestamp, AUTO_INCREMENT = 7 engine=innodb",
+		"add column t int, change ts ts timestamp, engine=innodb auto_increment=73425",
+	}
+	for _, statement := range statements {
+		parser := NewAlterTableParser()
+		err := parser.ParseAlterStatement(statement)
+		test.S(t).ExpectNil(err)
+		test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
+		test.S(t).ExpectTrue(parser.IsAutoIncrementDefined())
+	}
+}
+
 func TestParseAlterStatementTrivialRenames(t *testing.T) {
 	statement := "add column t int, change ts ts timestamp, CHANGE f `f` float, engine=innodb"
 	parser := NewAlterTableParser()
@@ -44,6 +66,7 @@ func TestParseAlterStatementTrivialRenames(t *testing.T) {
 	test.S(t).ExpectNil(err)
 	test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
 	test.S(t).ExpectFalse(parser.HasNonTrivialRenames())
+	test.S(t).ExpectFalse(parser.IsAutoIncrementDefined())
 	test.S(t).ExpectEquals(len(parser.columnRenameMap), 2)
 	test.S(t).ExpectEquals(parser.columnRenameMap["ts"], "ts")
 	test.S(t).ExpectEquals(parser.columnRenameMap["f"], "f")
@@ -64,6 +87,7 @@ func TestParseAlterStatementNonTrivial(t *testing.T) {
 		parser := NewAlterTableParser()
 		err := parser.ParseAlterStatement(statement)
 		test.S(t).ExpectNil(err)
+		test.S(t).ExpectFalse(parser.IsAutoIncrementDefined())
 		test.S(t).ExpectEquals(parser.alterStatementOptions, statement)
 		renames := parser.GetNonTrivialRenames()
 		test.S(t).ExpectEquals(len(renames), 2)

From 31069ae4f2334a66760fb3bb430319598d6de253 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 31 Dec 2020 11:06:37 +0200
Subject: [PATCH 08/17] support GetUint64

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 .../github.com/outbrain/golib/sqlutils/sqlutils.go  | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/vendor/github.com/outbrain/golib/sqlutils/sqlutils.go b/vendor/github.com/outbrain/golib/sqlutils/sqlutils.go
index 8d9869078..56761c655 100644
--- a/vendor/github.com/outbrain/golib/sqlutils/sqlutils.go
+++ b/vendor/github.com/outbrain/golib/sqlutils/sqlutils.go
@@ -117,6 +117,19 @@ func (this *RowMap) GetUintD(key string, def uint) uint {
 	return uint(res)
 }
 
+func (this *RowMap) GetUint64(key string) uint64 {
+	res, _ := strconv.ParseUint(this.GetString(key), 10, 0)
+	return res
+}
+
+func (this *RowMap) GetUint64D(key string, def uint64) uint64 {
+	res, err := strconv.ParseUint(this.GetString(key), 10, 0)
+	if err != nil {
+		return def
+	}
+	return uint64(res)
+}
+
 func (this *RowMap) GetBool(key string) bool {
 	return this.GetInt(key) != 0
 }

From 3d4dfaafd991eaea1bc7b47bfaf23e6d47ba3700 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 31 Dec 2020 11:06:53 +0200
Subject: [PATCH 09/17] minor update to test

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 localtests/autoinc-copy-deletes/create.sql | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/localtests/autoinc-copy-deletes/create.sql b/localtests/autoinc-copy-deletes/create.sql
index 0d668128d..2058b0b84 100644
--- a/localtests/autoinc-copy-deletes/create.sql
+++ b/localtests/autoinc-copy-deletes/create.sql
@@ -14,4 +14,4 @@ insert into gh_ost_test values (NULL, 23);
 insert into gh_ost_test values (NULL, 29);
 insert into gh_ost_test values (NULL, 31);
 insert into gh_ost_test values (NULL, 37);
-delete from gh_ost_test where id>5;
+delete from gh_ost_test where id>=5;

From 63219ab3e3629abcfe64630b37d31382599dbaef Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 31 Dec 2020 11:48:46 +0200
Subject: [PATCH 10/17] adding test for user defined AUTO_INCREMENT statement

---
 go/logic/inspect.go                             |  6 +++---
 .../create.sql                                  | 17 +++++++++++++++++
 .../expect_table_structure                      |  1 +
 .../extra_args                                  |  1 +
 4 files changed, 22 insertions(+), 3 deletions(-)
 create mode 100644 localtests/autoinc-copy-deletes-user-defined/create.sql
 create mode 100644 localtests/autoinc-copy-deletes-user-defined/expect_table_structure
 create mode 100644 localtests/autoinc-copy-deletes-user-defined/extra_args

diff --git a/go/logic/inspect.go b/go/logic/inspect.go
index 23f238ae6..d2633de3a 100644
--- a/go/logic/inspect.go
+++ b/go/logic/inspect.go
@@ -596,10 +596,10 @@ func (this *Inspector) applyColumnTypes(databaseName, tableName string, columnsL
 // getAutoIncrementValue get's the original table's AUTO_INCREMENT value, if exists (0 value if not exists)
 func (this *Inspector) getAutoIncrementValue(tableName string) (autoIncrement uint64, err error) {
 	query := `
-    SELECT
+		SELECT
 			AUTO_INCREMENT
-    FROM INFORMATION_SCHEMA.TABLES
-    WHERE
+		FROM INFORMATION_SCHEMA.TABLES
+		WHERE
 			TABLES.TABLE_SCHEMA = ?
 			AND TABLES.TABLE_NAME = ?
 			AND AUTO_INCREMENT IS NOT NULL
diff --git a/localtests/autoinc-copy-deletes-user-defined/create.sql b/localtests/autoinc-copy-deletes-user-defined/create.sql
new file mode 100644
index 000000000..2058b0b84
--- /dev/null
+++ b/localtests/autoinc-copy-deletes-user-defined/create.sql
@@ -0,0 +1,17 @@
+drop event if exists gh_ost_test;
+
+drop table if exists gh_ost_test;
+create table gh_ost_test (
+  id int auto_increment,
+  i int not null,
+  primary key(id)
+) auto_increment=1;
+
+insert into gh_ost_test values (NULL, 11);
+insert into gh_ost_test values (NULL, 13);
+insert into gh_ost_test values (NULL, 17);
+insert into gh_ost_test values (NULL, 23);
+insert into gh_ost_test values (NULL, 29);
+insert into gh_ost_test values (NULL, 31);
+insert into gh_ost_test values (NULL, 37);
+delete from gh_ost_test where id>=5;
diff --git a/localtests/autoinc-copy-deletes-user-defined/expect_table_structure b/localtests/autoinc-copy-deletes-user-defined/expect_table_structure
new file mode 100644
index 000000000..5e180af3b
--- /dev/null
+++ b/localtests/autoinc-copy-deletes-user-defined/expect_table_structure
@@ -0,0 +1 @@
+AUTO_INCREMENT=7
diff --git a/localtests/autoinc-copy-deletes-user-defined/extra_args b/localtests/autoinc-copy-deletes-user-defined/extra_args
new file mode 100644
index 000000000..cce91e1c7
--- /dev/null
+++ b/localtests/autoinc-copy-deletes-user-defined/extra_args
@@ -0,0 +1 @@
+--alter='AUTO_INCREMENT=7'

From 7202076c77c49d175e4283e69c4bad8b08e711ff Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Tue, 19 Jan 2021 13:27:00 +0200
Subject: [PATCH 11/17] Generated column as part of UNIQUE (or PRIMARY) KEY

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 .../generated-columns57-unique/create.sql     | 30 +++++++++++++++++++
 .../ignore_versions                           |  1 +
 2 files changed, 31 insertions(+)
 create mode 100644 localtests/generated-columns57-unique/create.sql
 create mode 100644 localtests/generated-columns57-unique/ignore_versions

diff --git a/localtests/generated-columns57-unique/create.sql b/localtests/generated-columns57-unique/create.sql
new file mode 100644
index 000000000..c75b5ff87
--- /dev/null
+++ b/localtests/generated-columns57-unique/create.sql
@@ -0,0 +1,30 @@
+drop table if exists gh_ost_test;
+create table gh_ost_test (
+  id int auto_increment,
+  `idb` varchar(36) CHARACTER SET utf8mb4 GENERATED ALWAYS AS (json_unquote(json_extract(`jsonobj`,_utf8mb4'$._id'))) STORED NOT NULL,
+  `jsonobj` json NOT NULL,
+  PRIMARY KEY (`id`,`idb`)
+) auto_increment=1;
+
+insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":2}'');
+insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":3}'');
+
+drop event if exists gh_ost_test;
+delimiter ;;
+create event gh_ost_test
+  on schedule every 1 second
+  starts current_timestamp
+  ends current_timestamp + interval 60 second
+  on completion not preserve
+  enable
+  do
+begin
+  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":5}'');
+  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":7}'');
+  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":11}'');
+  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":13}'');
+  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":17}'');
+  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":19}'');
+  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":23}'');
+  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":27}'');
+end ;;
diff --git a/localtests/generated-columns57-unique/ignore_versions b/localtests/generated-columns57-unique/ignore_versions
new file mode 100644
index 000000000..b6de5f8d9
--- /dev/null
+++ b/localtests/generated-columns57-unique/ignore_versions
@@ -0,0 +1 @@
+(5.5|5.6)

From b7b3bfbd34a405813549ffd1ce96032520d8cf73 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Tue, 19 Jan 2021 13:42:45 +0200
Subject: [PATCH 12/17] skip analysis of generated column data type in unique
 key

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 go/logic/inspect.go                           |  4 ++++
 .../generated-columns57-unique/create.sql     | 20 +++++++++----------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/go/logic/inspect.go b/go/logic/inspect.go
index fc7001770..f36df0f68 100644
--- a/go/logic/inspect.go
+++ b/go/logic/inspect.go
@@ -188,6 +188,10 @@ func (this *Inspector) inspectOriginalAndGhostTables() (err error) {
 	}
 
 	for _, column := range this.migrationContext.UniqueKey.Columns.Columns() {
+		if this.migrationContext.GhostTableVirtualColumns.GetColumn(column.Name) != nil {
+			// this is a virtual column
+			continue
+		}
 		if this.migrationContext.MappedSharedColumns.HasTimezoneConversion(column.Name) {
 			return fmt.Errorf("No support at this time for converting a column from DATETIME to TIMESTAMP that is also part of the chosen unique key. Column: %s, key: %s", column.Name, this.migrationContext.UniqueKey.Name)
 		}
diff --git a/localtests/generated-columns57-unique/create.sql b/localtests/generated-columns57-unique/create.sql
index c75b5ff87..7a63dd984 100644
--- a/localtests/generated-columns57-unique/create.sql
+++ b/localtests/generated-columns57-unique/create.sql
@@ -6,8 +6,8 @@ create table gh_ost_test (
   PRIMARY KEY (`id`,`idb`)
 ) auto_increment=1;
 
-insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":2}'');
-insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":3}'');
+insert into gh_ost_test (id, jsonobj) values (null, '{"_id":2}');
+insert into gh_ost_test (id, jsonobj) values (null, '{"_id":3}');
 
 drop event if exists gh_ost_test;
 delimiter ;;
@@ -19,12 +19,12 @@ create event gh_ost_test
   enable
   do
 begin
-  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":5}'');
-  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":7}'');
-  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":11}'');
-  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":13}'');
-  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":17}'');
-  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":19}'');
-  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":23}'');
-  insert into gh_ost_test (id, jsonobj) values (null, ''{"_id":27}'');
+  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":5}');
+  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":7}');
+  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":11}');
+  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":13}');
+  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":17}');
+  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":19}');
+  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":23}');
+  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":27}');
 end ;;

From 710c9ddda575c74b668f211241ea5eb2ec11bcfc Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Thu, 18 Feb 2021 10:44:47 +0200
Subject: [PATCH 13/17] All MySQL DBs limited to max 3 concurrent/idle
 connections

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 go/logic/throttler.go |  7 +++++--
 go/mysql/utils.go     | 30 ++++++++++++++++--------------
 2 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/go/logic/throttler.go b/go/logic/throttler.go
index d234ea663..abe8669e1 100644
--- a/go/logic/throttler.go
+++ b/go/logic/throttler.go
@@ -188,9 +188,12 @@ func (this *Throttler) collectControlReplicasLag() {
 		dbUri := connectionConfig.GetDBUri("information_schema")
 
 		var heartbeatValue string
-		if db, _, err := mysql.GetDB(this.migrationContext.Uuid, dbUri); err != nil {
+		db, _, err := mysql.GetDB(this.migrationContext.Uuid, dbUri)
+		if err != nil {
 			return lag, err
-		} else if err = db.QueryRow(replicationLagQuery).Scan(&heartbeatValue); err != nil {
+		}
+
+		if err := db.QueryRow(replicationLagQuery).Scan(&heartbeatValue); err != nil {
 			return lag, err
 		}
 
diff --git a/go/mysql/utils.go b/go/mysql/utils.go
index 17bb5fc32..43a228e18 100644
--- a/go/mysql/utils.go
+++ b/go/mysql/utils.go
@@ -18,8 +18,11 @@ import (
 	"github.com/outbrain/golib/sqlutils"
 )
 
-const MaxTableNameLength = 64
-const MaxReplicationPasswordLength = 32
+const (
+	MaxTableNameLength           = 64
+	MaxReplicationPasswordLength = 32
+	MaxDBPoolConnections         = 3
+)
 
 type ReplicationLagResult struct {
 	Key InstanceKey
@@ -39,23 +42,22 @@ func (this *ReplicationLagResult) HasLag() bool {
 var knownDBs map[string]*gosql.DB = make(map[string]*gosql.DB)
 var knownDBsMutex = &sync.Mutex{}
 
-func GetDB(migrationUuid string, mysql_uri string) (*gosql.DB, bool, error) {
+func GetDB(migrationUuid string, mysql_uri string) (db *gosql.DB, exists bool, err error) {
 	cacheKey := migrationUuid + ":" + mysql_uri
 
 	knownDBsMutex.Lock()
-	defer func() {
-		knownDBsMutex.Unlock()
-	}()
-
-	var exists bool
-	if _, exists = knownDBs[cacheKey]; !exists {
-		if db, err := gosql.Open("mysql", mysql_uri); err == nil {
-			knownDBs[cacheKey] = db
-		} else {
-			return db, exists, err
+	defer knownDBsMutex.Unlock()
+
+	if db, exists = knownDBs[cacheKey]; !exists {
+		db, err = gosql.Open("mysql", mysql_uri)
+		if err != nil {
+			return nil, false, err
 		}
+		db.SetMaxOpenConns(MaxDBPoolConnections)
+		db.SetMaxIdleConns(MaxDBPoolConnections)
+		knownDBs[cacheKey] = db
 	}
-	return knownDBs[cacheKey], exists, nil
+	return db, exists, nil
 }
 
 // GetReplicationLagFromSlaveStatus returns replication lag for a given db; via SHOW SLAVE STATUS

From 54000ab5169921f2cfd5541e06e89f7f2b65797c Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Sun, 7 Mar 2021 10:47:40 +0200
Subject: [PATCH 14/17] hooks: reporting GH_OST_ETA_SECONDS. ETA stored as part
 of migration context

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 go/base/context.go   |  9 +++++++++
 go/logic/hooks.go    |  1 +
 go/logic/migrator.go | 19 ++++++++++++++-----
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/go/base/context.go b/go/base/context.go
index 51b43dfc8..97d0d60b9 100644
--- a/go/base/context.go
+++ b/go/base/context.go
@@ -182,6 +182,7 @@ type MigrationContext struct {
 	lastHeartbeatOnChangelogMutex          *sync.Mutex
 	CurrentLag                             int64
 	currentProgress                        uint64
+	etaNanoseonds                          int64
 	ThrottleHTTPStatusCode                 int64
 	controlReplicasLagResult               mysql.ReplicationLagResult
 	TotalRowsCopied                        int64
@@ -474,6 +475,14 @@ func (this *MigrationContext) SetProgressPct(progressPct float64) {
 	atomic.StoreUint64(&this.currentProgress, math.Float64bits(progressPct))
 }
 
+func (this *MigrationContext) GetETADuration() time.Duration {
+	return time.Duration(atomic.LoadInt64(&this.etaNanoseonds))
+}
+
+func (this *MigrationContext) SetETADuration(etaDuration time.Duration) {
+	atomic.StoreInt64(&this.etaNanoseonds, etaDuration.Nanoseconds())
+}
+
 // math.Float64bits([f=0..100])
 
 // GetTotalRowsCopied returns the accurate number of rows being copied (affected)
diff --git a/go/logic/hooks.go b/go/logic/hooks.go
index 71f070ce3..ea7822e71 100644
--- a/go/logic/hooks.go
+++ b/go/logic/hooks.go
@@ -66,6 +66,7 @@ func (this *HooksExecutor) applyEnvironmentVariables(extraVariables ...string) [
 	env = append(env, fmt.Sprintf("GH_OST_INSPECTED_LAG=%f", this.migrationContext.GetCurrentLagDuration().Seconds()))
 	env = append(env, fmt.Sprintf("GH_OST_HEARTBEAT_LAG=%f", this.migrationContext.TimeSinceLastHeartbeatOnChangelog().Seconds()))
 	env = append(env, fmt.Sprintf("GH_OST_PROGRESS=%f", this.migrationContext.GetProgressPct()))
+	env = append(env, fmt.Sprintf("GH_OST_ETA_SECONDS=%f", this.migrationContext.GetETADuration().Seconds()))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT=%s", this.migrationContext.HooksHintMessage))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT_OWNER=%s", this.migrationContext.HooksHintOwner))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT_TOKEN=%s", this.migrationContext.HooksHintToken))
diff --git a/go/logic/migrator.go b/go/logic/migrator.go
index dfddccffc..e34b2a707 100644
--- a/go/logic/migrator.go
+++ b/go/logic/migrator.go
@@ -939,20 +939,29 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {
 	}
 
 	var etaSeconds float64 = math.MaxFloat64
-	eta := "N/A"
+	var etaDuration = time.Duration(math.MaxInt64)
 	if progressPct >= 100.0 {
-		eta = "due"
+		etaDuration = 0
 	} else if progressPct >= 0.1 {
 		elapsedRowCopySeconds := this.migrationContext.ElapsedRowCopyTime().Seconds()
 		totalExpectedSeconds := elapsedRowCopySeconds * float64(rowsEstimate) / float64(totalRowsCopied)
 		etaSeconds = totalExpectedSeconds - elapsedRowCopySeconds
 		if etaSeconds >= 0 {
-			etaDuration := time.Duration(etaSeconds) * time.Second
-			eta = base.PrettifyDurationOutput(etaDuration)
+			etaDuration = time.Duration(etaSeconds) * time.Second
 		} else {
-			eta = "due"
+			etaDuration = 0
 		}
 	}
+	this.migrationContext.SetETADuration(etaDuration)
+	var eta string
+	switch etaDuration {
+	case 0:
+		eta = "due"
+	case time.Duration(math.MaxInt64):
+		eta = "N/A"
+	default:
+		eta = base.PrettifyDurationOutput(etaDuration)
+	}
 
 	state := "migrating"
 	if atomic.LoadInt64(&this.migrationContext.CountingRowsFlag) > 0 && !this.migrationContext.ConcurrentCountTableRows {

From 51719a2b769f72f5eee3c869fa1b7eb602d376fd Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Sun, 7 Mar 2021 11:11:50 +0200
Subject: [PATCH 15/17] GH_OST_ETA_NANOSECONDS

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 go/logic/hooks.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/go/logic/hooks.go b/go/logic/hooks.go
index ea7822e71..481c3dfe1 100644
--- a/go/logic/hooks.go
+++ b/go/logic/hooks.go
@@ -66,7 +66,7 @@ func (this *HooksExecutor) applyEnvironmentVariables(extraVariables ...string) [
 	env = append(env, fmt.Sprintf("GH_OST_INSPECTED_LAG=%f", this.migrationContext.GetCurrentLagDuration().Seconds()))
 	env = append(env, fmt.Sprintf("GH_OST_HEARTBEAT_LAG=%f", this.migrationContext.TimeSinceLastHeartbeatOnChangelog().Seconds()))
 	env = append(env, fmt.Sprintf("GH_OST_PROGRESS=%f", this.migrationContext.GetProgressPct()))
-	env = append(env, fmt.Sprintf("GH_OST_ETA_SECONDS=%f", this.migrationContext.GetETADuration().Seconds()))
+	env = append(env, fmt.Sprintf("GH_OST_ETA_NANOSECONDS=%d", this.migrationContext.GetETADuration().Nanoseconds()))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT=%s", this.migrationContext.HooksHintMessage))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT_OWNER=%s", this.migrationContext.HooksHintOwner))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT_TOKEN=%s", this.migrationContext.HooksHintToken))

From 76b9c16a68b43f24bfd658cfee8a71cf7dd74806 Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Sun, 7 Mar 2021 11:27:50 +0200
Subject: [PATCH 16/17] N/A denoted by negative value

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 go/base/context.go   | 5 +++++
 go/logic/hooks.go    | 2 +-
 go/logic/migrator.go | 4 ++--
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/go/base/context.go b/go/base/context.go
index 97d0d60b9..414ead459 100644
--- a/go/base/context.go
+++ b/go/base/context.go
@@ -483,6 +483,11 @@ func (this *MigrationContext) SetETADuration(etaDuration time.Duration) {
 	atomic.StoreInt64(&this.etaNanoseonds, etaDuration.Nanoseconds())
 }
 
+func (this *MigrationContext) GetETASeconds() int64 {
+	nano := atomic.LoadInt64(&this.etaNanoseonds)
+	return nano / int64(time.Second)
+}
+
 // math.Float64bits([f=0..100])
 
 // GetTotalRowsCopied returns the accurate number of rows being copied (affected)
diff --git a/go/logic/hooks.go b/go/logic/hooks.go
index 481c3dfe1..2275ede51 100644
--- a/go/logic/hooks.go
+++ b/go/logic/hooks.go
@@ -66,7 +66,7 @@ func (this *HooksExecutor) applyEnvironmentVariables(extraVariables ...string) [
 	env = append(env, fmt.Sprintf("GH_OST_INSPECTED_LAG=%f", this.migrationContext.GetCurrentLagDuration().Seconds()))
 	env = append(env, fmt.Sprintf("GH_OST_HEARTBEAT_LAG=%f", this.migrationContext.TimeSinceLastHeartbeatOnChangelog().Seconds()))
 	env = append(env, fmt.Sprintf("GH_OST_PROGRESS=%f", this.migrationContext.GetProgressPct()))
-	env = append(env, fmt.Sprintf("GH_OST_ETA_NANOSECONDS=%d", this.migrationContext.GetETADuration().Nanoseconds()))
+	env = append(env, fmt.Sprintf("GH_OST_ETA_SECONDS=%d", this.migrationContext.GetETASeconds()))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT=%s", this.migrationContext.HooksHintMessage))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT_OWNER=%s", this.migrationContext.HooksHintOwner))
 	env = append(env, fmt.Sprintf("GH_OST_HOOKS_HINT_TOKEN=%s", this.migrationContext.HooksHintToken))
diff --git a/go/logic/migrator.go b/go/logic/migrator.go
index e34b2a707..9ef90e152 100644
--- a/go/logic/migrator.go
+++ b/go/logic/migrator.go
@@ -939,7 +939,7 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {
 	}
 
 	var etaSeconds float64 = math.MaxFloat64
-	var etaDuration = time.Duration(math.MaxInt64)
+	var etaDuration = time.Duration(math.MinInt64)
 	if progressPct >= 100.0 {
 		etaDuration = 0
 	} else if progressPct >= 0.1 {
@@ -957,7 +957,7 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {
 	switch etaDuration {
 	case 0:
 		eta = "due"
-	case time.Duration(math.MaxInt64):
+	case time.Duration(math.MinInt64):
 		eta = "N/A"
 	default:
 		eta = base.PrettifyDurationOutput(etaDuration)

From b688c58a45dfc34fe4bc59eb84d1c3504bc8c2ac Mon Sep 17 00:00:00 2001
From: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Date: Sun, 7 Mar 2021 14:16:04 +0200
Subject: [PATCH 17/17] ETAUnknown constant

Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
---
 go/base/context.go   | 5 +++++
 go/logic/migrator.go | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/go/base/context.go b/go/base/context.go
index 414ead459..b9badc43b 100644
--- a/go/base/context.go
+++ b/go/base/context.go
@@ -52,6 +52,7 @@ const (
 const (
 	HTTPStatusOK       = 200
 	MaxEventsBatchSize = 1000
+	ETAUnknown         = math.MinInt64
 )
 
 var (
@@ -268,6 +269,7 @@ func NewMigrationContext() *MigrationContext {
 		MaxLagMillisecondsThrottleThreshold: 1500,
 		CutOverLockTimeoutSeconds:           3,
 		DMLBatchSize:                        10,
+		etaNanoseonds:                       ETAUnknown,
 		maxLoad:                             NewLoadMap(),
 		criticalLoad:                        NewLoadMap(),
 		throttleMutex:                       &sync.Mutex{},
@@ -485,6 +487,9 @@ func (this *MigrationContext) SetETADuration(etaDuration time.Duration) {
 
 func (this *MigrationContext) GetETASeconds() int64 {
 	nano := atomic.LoadInt64(&this.etaNanoseonds)
+	if nano < 0 {
+		return ETAUnknown
+	}
 	return nano / int64(time.Second)
 }
 
diff --git a/go/logic/migrator.go b/go/logic/migrator.go
index 9ef90e152..c12c21fc3 100644
--- a/go/logic/migrator.go
+++ b/go/logic/migrator.go
@@ -939,7 +939,7 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {
 	}
 
 	var etaSeconds float64 = math.MaxFloat64
-	var etaDuration = time.Duration(math.MinInt64)
+	var etaDuration = time.Duration(base.ETAUnknown)
 	if progressPct >= 100.0 {
 		etaDuration = 0
 	} else if progressPct >= 0.1 {
@@ -957,7 +957,7 @@ func (this *Migrator) printStatus(rule PrintStatusRule, writers ...io.Writer) {
 	switch etaDuration {
 	case 0:
 		eta = "due"
-	case time.Duration(math.MinInt64):
+	case time.Duration(base.ETAUnknown):
 		eta = "N/A"
 	default:
 		eta = base.PrettifyDurationOutput(etaDuration)