MDEV-16213: Improvements and adjustments to Travis config

Several improvements have been made so that builds run
faster and with fewer canceled jobs:

* Set ccache max size to 1GB. Was 512MB for Linux
(too low for MariaDB) and 5GB on macOS with defaults;

* Don't install libasan in Travis if not necessary.
Sicne ASAN is disabled for the time being, save
time/resources for other steps;

* Decrease number of parallel processes. To prevent
resource exhaustion leading to poor performance. According
to Travis docs, a max of 4 concurrent processses should be
run per job:
https://docs.travis-ci.com/user/common-build-problems/#My-build-script-is-killed-without-any-error

* Reconsider tests exec order and split huge main and rocksdb
test suites into their own job, decreasing the chance of going
over the Travis job execution limit and getting killed;

* Increase Travis testcase-timeout to 4 minutes. Occasionally
on Ubuntu target and frequently on macOS, many tests in main,
rpl, binlog suites take longer than 2 minutes, resulting in
many jobs failing, when in reality the failing tests didn't
get a chance to complete. From my testing, along with the other
speedups, i.e. increasing ccache size, a timeout of 4 minutes
should be Ok.  Revert to 3 minutes of necessary.

* Build with GCC and Clang version 5,6 only.

* Rename GCC_VERSION to CC_VERSION for clarity. We are using
two compilers after all, GCC and Clang.

* Stop using somewhat obsolete Clang4 in Travis. Also, was the
reason for the failing test suites in MDEV-15430.

.travis.compiler.sh

@@ -7,10 +7,6 @@ if [[ "${TRAVIS_OS_NAME}" == 'linux' ]]; then
     if which ccache ; then
       CMAKE_OPT="${CMAKE_OPT} -DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache"
     fi
-    case ${GCC_VERSION} in
-      5) CXX=clang++-4.0 ;;
-      6) CXX=clang++-5.0 ;;
-    esac
     export CXX CC=${CXX/++/}
   elif [[ "${CXX}" == 'g++' ]]; then
     CMAKE_OPT=""
@@ -18,16 +14,16 @@ if [[ "${TRAVIS_OS_NAME}" == 'linux' ]]; then
       CMAKE_OPT="${CMAKE_OPT} -DWITHOUT_TOKUDB_STORAGE_ENGINE=TRUE"
       CMAKE_OPT="${CMAKE_OPT} -DWITHOUT_MROONGA_STORAGE_ENGINE=TRUE"
     fi
-    export CXX=g++-${GCC_VERSION}
-    export CC=gcc-${GCC_VERSION}
+    export CXX=g++-${CC_VERSION}
+    export CC=gcc-${CC_VERSION}
   fi
-  if [[ ${GCC_VERSION} == 6 ]]; then
+  if [[ ${CC_VERSION} == 6 ]]; then
          wget http://mirrors.kernel.org/ubuntu/pool/universe/p/percona-xtradb-cluster-galera-2.x/percona-xtradb-cluster-galera-2.x_165-0ubuntu1_amd64.deb ;
          ar vx percona-xtradb-cluster-galera-2.x_165-0ubuntu1_amd64.deb
          tar -xJvf data.tar.xz
          export WSREP_PROVIDER=$PWD/usr/lib/libgalera_smm.so
          MYSQL_TEST_SUITES="${MYSQL_TEST_SUITES},wsrep"
-  #elif [[ ${GCC_VERSION} != 5 ]]; then
+  #elif [[ ${CC_VERSION} != 5 ]]; then
     #CMAKE_OPT="${CMAKE_OPT} -DWITH_ASAN=ON"
   fi
 else

.travis.yml

@@ -18,16 +18,18 @@ compiler:
 
 cache:
   apt: true
-  ccache: true # Does not currently work for clang builds: https://github.com/travis-ci/travis-ci/issues/6201
+  ccache: true
   directories:
     - /usr/local/Cellar # Fails do to permission error: https://github.com/travis-ci/travis-ci/issues/8092
 
 env:
   matrix:
-    - GCC_VERSION=4.8 TYPE=RelWithDebInfo MYSQL_TEST_SUITES=rpl
-    - GCC_VERSION=5   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=main,archive,optimizer_unfixed_bugs,parts,sys_vars,unit,vcol,innodb,innodb_gis,innodb_zip,innodb_fts
-    - GCC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=binlog,binlog_encryption,encryption,rocksdb
-    - GCC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=csv,federated,funcs_1,funcs_2,gcol,handler,heap,json,maria,perfschema,plugins,multi_source,roles
+    - CC_VERSION=5   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=main
+    - CC_VERSION=5   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=archive,optimizer_unfixed_bugs,parts,sys_vars,unit,vcol,innodb,innodb_gis,innodb_zip,innodb_fts
+    - CC_VERSION=5   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=rpl
+    - CC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=binlog,binlog_encryption,encryption
+    - CC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=rocksdb
+    - CC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=csv,federated,funcs_1,funcs_2,gcol,handler,heap,json,maria,perfschema,plugins,multi_source,roles
 
 matrix:
   exclude:
@@ -81,39 +83,45 @@ matrix:
       # https://github.com/travis-ci/travis-ci/issues/7062 - /run/shm isn't writable or executable
       # in trusty containers
         - export MTR_MEM=/tmp
-        - env DEB_BUILD_OPTIONS="parallel=6" debian/autobake-deb.sh;
+        - env DEB_BUILD_OPTIONS="parallel=4" debian/autobake-deb.sh;
         - ccache --show-stats
   # Until OSX becomes a bit more stable: MDEV-12435
   allow_failures:
     - os: osx
       compiler: clang
-      env: GCC_VERSION=4.8 TYPE=RelWithDebInfo MYSQL_TEST_SUITES=rpl
+      env: CC_VERSION=5   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=rpl
     - os: osx
       compiler: clang
-      env: GCC_VERSION=5   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=main,archive,optimizer_unfixed_bugs,parts,sys_vars,unit,vcol,innodb,innodb_gis,innodb_zip,innodb_fts
+      env: CC_VERSION=5   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=main
     - os: osx
       compiler: clang
-      env: GCC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=binlog,binlog_encryption,encryption,rocksdb
+      env: CC_VERSION=5   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=archive,optimizer_unfixed_bugs,parts,sys_vars,unit,vcol,innodb,innodb_gis,innodb_zip,innodb_fts
     - os: osx
       compiler: clang
-      env: GCC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=csv,federated,funcs_1,funcs_2,gcol,handler,heap,json,maria,perfschema,plugins,multi_source,roles
+      env: CC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=binlog,binlog_encryption,encryption
+    - os: osx
+      compiler: clang
+      env: CC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=rocksdb
+    - os: osx
+      compiler: clang
+      env: CC_VERSION=6   TYPE=RelWithDebInfo MYSQL_TEST_SUITES=csv,federated,funcs_1,funcs_2,gcol,handler,heap,json,maria,perfschema,plugins,multi_source,roles
 
 addons:
   apt:
     sources:
       - ubuntu-toolchain-r-test
-      - llvm-toolchain-trusty-4.0
       - sourceline: 'deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-5.0 main'
+      - sourceline: 'deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-6.0 main'
     packages: # make sure these include all compilers and all build dependencies (see list above)
       - gcc-5
       - g++-5
       - gcc-6
       - g++-6
-      - clang-4.0
-      - llvm-4.0-dev
       - clang-5.0
       - llvm-5.0-dev
-      - libasan0
+      - clang-6.0
+      - llvm-6.0-dev
+#      - libasan0
       - bison
       - chrpath
       - cmake
@@ -154,19 +162,22 @@ before_install:
 
 script:
   - ccache --version
-# Clang:
-#   mroonga just generates too many warnings with clang and travis stops the job
-#   tokudb has fatal warnings
+  - ccache --show-stats
+  - ccache --max-size=1000M
+# following modules are disabled after sourcing .travis.compiler.sh:
+# clang disabled: mroonga just generates too many warnings with clang and travis stops the job
+# cland disabled: tokudb has fatal warnings
+# gcc/rpl: tokudb and mroonga
   - source .travis.compiler.sh
   - cmake .
            -DCMAKE_BUILD_TYPE=${TYPE}
            ${CMAKE_OPT}
            -DWITH_SSL=system -DWITH_ZLIB=system -DPLUGIN_AWS_KEY_MANAGEMENT=DYNAMIC -DAWS_SDK_EXTERNAL_PROJECT=ON
-  - make -j 6
+  - make -j 4
   - cd mysql-test
 # With ASAN --thread-stack=400K to account for overhead
-# Test timeout needs to be 10(minutes) or less due to travis out timeout
-  - ./mtr --force --max-test-fail=20 --parallel=6 --testcase-timeout=2
+# Test timeout needs to be 10 (minutes) or less due to travis job timeout
+  - ./mtr --force --max-test-fail=20 --parallel=4 --testcase-timeout=4
          --suite=${MYSQL_TEST_SUITES}
          --skip-test-list=unstable-tests
          --skip-test=binlog.binlog_unsafe