Note: Tested in Oracle 19c on Linux.
1. ORA-29532 java.lang.OutOfMemoryError
Nenad's Blog: Troubleshooting java.lang.OutOfMemoryError in the Oracle Database made a deep investigation of ORA-29532 OutOfMemoryError, and found the internal hard-coded maximum total size in bytes: 536870895 It shows that for int[] array size of 134217723 (0x7FFFFFB, about 128MB Java int), there is no memory error. However, adding just one additional element will cause OutOfMemoryError (By default, Java int data type is a 32-bit signed).
We will explore further ORA-29532 OutOfMemoryError and list the 4 hard-coded integer array size limits on 4 respective Java integer Primitive Data Types.
At first, we copy Nenad's test code and add one method for byte[].
drop java source "Demo";
create or replace and compile java source named "Demo" as
public class Demo {
public static void defineIntArray(int p_size) throws Exception {
//Test of ORA-29532: Java call terminated by uncaught Java exception: java.lang.OutOfMemoryError
//copy from https://nenadnoveljic.com/blog/troubleshooting-java-lang-outofmemoryerror-in-the-oracle-database/
int[] v = new int[p_size];
System.out.println("OracleJvm int[].length: " + v.length);
}
public static void defineByteArray(int p_size) throws Exception {
byte[] v = new byte[p_size];
System.out.println("OracleJvm byte[].length: " + v.length);
}
}
/
create Or replace procedure p_define_int_array (p_size number)
as language java name 'Demo.defineIntArray(int)' ;
/
create Or replace procedure p_define_byte_array (p_size number)
as language java name 'Demo.defineByteArray(int)' ;
/
SQL > exec p_define_int_array(134217723);
OracleJvm int[].length: 134217723
SQL > exec p_define_int_array(134217724);
Exception in thread "Root Thread" java.lang.OutOfMemoryError
at Demo.defineIntArray(Demo:29)
BEGIN p_define_int_array(134217724); END;
*
ERROR at line 1:
ORA-29532: Java call terminated by uncaught Java exception: java.lang.OutOfMemoryError
ORA-06512: at "K.P_DEFINE_INT_ARRAY", line 1
ORA-06512: at line 1
alter system set java_jit_enabled=false;
# --------------------------- long, max: 0x3fffffd ---------------------------
<+107>: cmp %r13d,%eax
<+110>: jl 0x583c639 <joe_make_primitive_array+121>
<+112>: cmp $0x3fffffd,%rdx
<+119>: jbe 0x583c64b <joe_make_primitive_array+139>
<+121>: lea 0x11b9ed78(%rip),%rax # 0x173db3b8 <ioa_ko_j_l_out_of_memory_error>
<+128>: mov %r15,%rdi
<+131>: mov (%rax),%rsi
<+134>: callq 0x58459f0 <joe_blow>
<+139>: mov 0x1f1(%r15),%r9
# --------------------------- int, max: 0x7fffffb ---------------------------
<+299>: cmp %r13d,%eax
<+302>: jl 0x583c6f9 <joe_make_primitive_array+313>
<+304>: cmp $0x7fffffb,%rdx
<+311>: jbe 0x583c70b <joe_make_primitive_array+331>
<+313>: lea 0x11b9ecb8(%rip),%rax # 0x173db3b8 <ioa_ko_j_l_out_of_memory_error>
<+320>: mov %r15,%rdi
<+323>: mov (%rax),%rsi
<+326>: callq 0x58459f0 <joe_blow>
<+331>: mov 0x1f1(%r15),%r9
# --------------------------- short, max: 0xffffff7 ---------------------------
<+491>: cmp %r13d,%eax
<+494>: jl 0x583c7b9 <joe_make_primitive_array+505>
<+496>: cmp $0xffffff7,%rdx
<+503>: jbe 0x583c7cb <joe_make_primitive_array+523>
<+505>: lea 0x11b9ebf8(%rip),%rax # 0x173db3b8 <ioa_ko_j_l_out_of_memory_error>
<+512>: mov %r15,%rdi
<+515>: mov (%rax),%rsi
<+518>: callq 0x58459f0 <joe_blow>
<+523>: mov 0x1f1(%r15),%r9
# --------------------------- byte, max: 0x1fffffef ---------------------------
<+676>: cmp %r13d,%eax
<+679>: jl 0x583c872 <joe_make_primitive_array+690>
<+681>: cmp $0x1fffffef,%rdx
<+688>: jbe 0x583c884 <joe_make_primitive_array+708>
<+690>: lea 0x11b9eb3f(%rip),%rax # 0x173db3b8 <ioa_ko_j_l_out_of_memory_error>
<+697>: mov %r15,%rdi
<+700>: mov (%rax),%rsi
<+703>: callq 0x58459f0 <joe_blow>
<+708>: mov 0x1f1(%r15),%r9
long (8 bytes, 0x3fffffd =67108861 )
int (4 bytes, 0x7fffffb =134217723)
short (2 bytes, 0xffffff7 =268435447)
byte (1 byte, 0x1fffffef=536870895)
For example, for data type int, the input parameter array size (register rdx, passed as arg2 to joe_make_primitive_array) is checked against fixed constant 0x7fffffb (134217723, a hard-coded value). According to cmp status flags, create array if rdx below or equal to 0x7fffffb (%rdx - $0x7fffffb, CF=1 or ZF=1); otherwise continue to "ioa_ko_j_l_out_of_memory_error".
<+304>: cmp $0x7fffffb,%rdx
<+311>: jbe 0x583c70b <joe_make_primitive_array+331>
<+313>: lea 0x11b9ecb8(%rip),%rax # 0x173db3b8 <ioa_ko_j_l_out_of_memory_error>
<+299>: cmp %r13d,%eax
<+302>: jl 0x583c6f9 <joe_make_primitive_array+313>
SQL > exec p_define_byte_array(536870895);
OracleJvm byte[].length: 536870895
SQL > exec p_define_byte_array(536870896);
Exception in thread "Root Thread" java.lang.OutOfMemoryError
at Demo.defineByteArray(Demo:31)
BEGIN p_define_byte_array(536870896); END;
*
ERROR at line 1:
ORA-29532: Java call terminated by uncaught Java exception: java.lang.OutOfMemoryError
ORA-06512: at "K.P_DEFINE_BYTE_ARRAY", line 1
ORA-06512: at line 1
Symptoms A database routine implemented as a Java Stored procedure receives the following error. ORA-29532: Java call terminated by uncaught Java exception: java.lang.OutOfMemoryError This routine may have worked previously or it may be brand new development. Cause The DB JVM does not have enough session Heap Memory. This error occurs when a Java Stored Procedure (ie. a PL/SQL routine where the body is implemented in Java ) does not have enough Heap space to work with the amount of data being processed. If this were a client-side java program using the Java Runtime Engine (JRE) (ie. java.exe), one would use the -Xmx parameter to configure the Heap Memory. However, as the Oracle DB JVM is running in the process space of the Oracle executable, there is no way to use the -Xmx switch. The JVM has a default Heap Size (512MB since 11.2) but it is also configurable using a method in the "Java Runtime" class called "oracle.aurora.vm.OracleRuntime". Along with other "java runtime" related switches, this class contains a couple methods that can be used to manage the Java Heap Size. Therefore, if you encounter the OutOfMemoryError and need to increase from either the default or a previous configured amount, you can use oracle.aurora.vm.OracleRuntime.setMaxMemorySize to allocate more memory for the Java Heap.The MOS Note described that "Oracle DB JVM is running in the process space of the Oracle executable" and had one hint about 512MB: "The JVM has a default Heap Size (512MB since 11.2)". As one Solution, MOS Note provided following workaround.
create or replace package Java_Runtime is
function getHeapSize return number;
function setHeapSize(num number) return number;
end Java_Runtime;
/
create or replace package body Java_Runtime is
function getHeapSize return number is
language java name 'oracle.aurora.vm.OracleRuntime.getMaxMemorySize() returns long';
function setHeapSize(num number) return number is
language java name 'oracle.aurora.vm.OracleRuntime.setMaxMemorySize(long) returns long';
end Java_Runtime;
/
declare
heap_return_val NUMBER;
begin
-- MOS code has a typo, setMaxMemorySize should be setHeapSize
-- heap_return_val := Java_Runtime.setMaxMemorySize(1024*1024*1024);
dbms_output.put_line('HeapSize Before Set: '||Java_Runtime.getHeapSize);
heap_return_val := Java_Runtime.setHeapSize(1024*1024*1024);
dbms_output.put_line('HeapSize After Set: '||Java_Runtime.getHeapSize);
-- MOS code
-- MY_JAVA_STORED_PROC(...);
p_define_int_array(134217724);
end;
/
HeapSize Before Set: 536870912
HeapSize After Set: 1073741824
declare
*
ERROR at line 1:
ORA-29532: Java call terminated by uncaught Java exception: java.lang.OutOfMemoryError
ORA-06512: at "K.P_DEFINE_INT_ARRAY", line 1
ORA-06512: at line 14
2. ORA-27102: out of memory
Blog: Oracle JVM Java OutOfMemoryError and lazy GC was trying to bring up some discussions on OracleJVM OutOfMemoryError in connection with lazy GC.
The first test in the Blog is to allocate 511MB byte array:
SQL > exec createBuffer512(1024*1024*511);
PL/SQL procedure successfully completed
but the second test with 512MB:
SQL > exec createBuffer512(1024*1024*512);
ERROR at line 1:
ORA-29532: Java call terminated by uncaught Java exception: java.lang.OutOfMemoryError
ORA-06512: at "K.CREATEBUFFER512", line 1
ORA-06512: at line 1
We can see that above hard-coded byte[] limit of 536870895 (0x1fffffef) is between 511MB and 512MB.
1024*1024*512=536870912 > 536870895 > 535822336=1024*1024*511.
SQL > exec createBuffer512_loop(511, 1, 1);
Step -- 1 --, Buffer Size (MB) = 1
Step -- 2 --, Buffer Size (MB) = 2
Step -- 3 --, Buffer Size (MB) = 3
...
Step -- 202 --, Buffer Size (MB) = 202
Step -- 203 --, Buffer Size (MB) = 203
ERROR at line 1:
ORA-27102: out of memory
Linux-x86_64 Error: 12: Cannot allocate memory
Additional information: 12394
Additional information: 218103808
ORA-06512: at "K.CREATEBUFFER512", line 1
ORA-06512: at "K.CREATEBUFFER512_LOOP", line 8
ORA-06512: at line 1
Make a 27102 trace:
alter session set max_dump_file_size = unlimited;
alter session set tracefile_identifier='ORA27102_trc3';
alter session set events '27102 trace name errorstack level 3';
exec createBuffer512_loop(511, 1, 1);
----- Error Stack Dump -----
Linux-x86_64 Error: 12: Cannot allocate memory
Additional information: 12394
Additional information: 218103808
BEGIN createBuffer512_loop(511, 1, 1); END;
----- PL/SQL Call Stack -----
object line object
handle number name
0x91948d30 1 procedure K.CREATEBUFFER512
0x8ef98db0 8 procedure K.CREATEBUFFER512_LOOP
0x8ca47e38 1 anonymous block
----- Call Stack Trace -----
FRAME [12] (dbgePostErrorKGE()+1066 -> dbkdChkEventRdbmsErr())
FRAME [13] (dbkePostKGE_kgsf()+71 -> dbgePostErrorKGE())
FRAME [14] (kgerscl()+546 -> dbkePostKGE_kgsf())
FRAME [15] (kgecss()+69 -> kgerscl())
FRAME [16] (ksmrf_init_alloc()+821 -> kgecss())
CALL TYPE: call ERROR SIGNALED: yes COMPONENT: KSM
FRAME [17] (ksmapg()+521 -> ksmrf_init_alloc())
FRAME [18] (kgh_invoke_alloc_cb()+162 -> ksmapg())
RDI 000000000D000000 RSI 00007F4D777511E0 RDX 000000000CE2D8B0
FRAME [19] (kghgex()+2713 -> kgh_invoke_alloc_cb())
FRAME [20] (kghfnd()+376 -> kghgex())
FRAME [21] (kghalo()+4908 -> kghfnd())
FRAME [22] (kghgex()+593 -> kghalo())
FRAME [23] (kghfnd()+376 -> kghgex())
FRAME [24] (kghalo()+4908 -> kghfnd())
FRAME [25] (kghgex()+593 -> kghalo())
FRAME [26] (kghalf()+617 -> kghgex())
FRAME [27] (ioc_allocate0()+1094 -> kghalf())
FRAME [28] (iocbf_allocate0()+53 -> ioc_allocate0())
FRAME [29] (ioc_do_call()+1297 -> iocbf_allocate0())
FRAME [30] (joet_switched_env_callback()+376 -> ioc_do_call())
FRAME [31] (ioct_allocate0()+79 -> joet_switched_env_callback())
FRAME [32] (eoa_new_mman_segment()+368 -> ioct_allocate0())
FRAME [33] (eoa_new_mswmem_chunk()+66 -> eoa_new_mman_segment())
FRAME [34] (eomsw_allocate_block()+229 -> eoa_new_mswmem_chunk())
FRAME [35] (eoa_alloc_mswmem_object_no_gc()+2037 -> eomsw_allocate_block())
FRAME [36] (eoa_alloc_mswmem_object()+48 -> eoa_alloc_mswmem_object_no_gc())
FRAME [37] (eoa_new_ool_alloc()+508 -> eoa_alloc_mswmem_object())
FRAME [38] (joe_make_primitive_array()+828 -> eoa_new_ool_alloc())
FRAME [39] (joe_run_vm()+15736 -> joe_make_primitive_array())
FRAME [40] (joe_run()+608 -> joe_run_vm())
FRAME [41] (joe_invoke()+1156 -> joe_run())
FRAME [42] (joet_aux_thread_main()+1674 -> joe_invoke())
FRAME [43] (seoa_note_stack_outside()+34 -> joet_aux_thread_main())
FRAME [44] (joet_thread_main()+64 -> seoa_note_stack_outside())
FRAME [45] (sjontlo_initialize()+178 -> joet_thread_main())
FRAME [46] (joe_enter_vm()+1197 -> sjontlo_initialize())
FRAME [47] (ioei_call_java()+4716 -> joe_enter_vm())
FRAME [48] (ioesub_CALL_JAVA()+569 -> ioei_call_java())
FRAME [49] (seoa_note_stack_outside()+34 -> ioesub_CALL_JAVA())
FRAME [50] (ioe_call_java()+292 -> seoa_note_stack_outside())
FRAME [51] (jox_invoke_java_()+4133 -> ioe_call_java())
FRAME [52] (kkxmjexe()+1493 -> jox_invoke_java_())
Session Wait History:
0: waited for 'PGA memory operation'
=0xd000000, =0x2, =0x0
"Additional information: 12394" is not clear.
"Additional information: 218103808" points out P1 parameter in Event "PGA memory operation" (12.2 new introduced), which also appears in "RDI 000000000D000000" of kgh_invoke_alloc_cb call (0xd000000 = 218103808).
In the above call stack, there is a subroutine "FRAME [35] (eoa_alloc_mswmem_object_no_gc()", with suffix "no_gc".
"FRAME [38] (joe_make_primitive_array()+828 -> eoa_new_ool_alloc())" shows that "joe_make_primitive_array" already passed line <+708> of byte array size check (see above disassembled code), and is calling "eoa_new_ool_alloc".
Occasionally, session is terminated:
SQL > exec createBuffer512_loop(511, 1, 1);
ERROR:
ORA-03114: not connected to ORACLE
ORA-03113: end-of-file on communication channel
Process ID: 14461
Session ID: 907 Serial number: 50430
Out of memory: Kill process 14461 (oracle_14461_c0) score 781 or sacrifice child
Killed process 14461 (oracle_14461_c0) total-vm:23745148kB, anon-rss:18595960kB, file-rss:132kB, shmem-rss:538232kB
3. Out of Memory Error Application Handling
If PL/SQL applications hit out of Memory Error even under the discussed hard-coded limit, one possible workaround is try to catch the error, invoke dbms_java.endsession to release memory, and then re-try the application as follows:
set serveroutput on size 50000;
exec dbms_java.set_output(50000);
declare
java_oom_29532 exception;
pragma exception_init(java_oom_29532, -29532);
l_es_ret varchar2(100);
begin
p_define_int_array(134217724); -- only illustrative demo, real application should use size below the limit
exception
when java_oom_29532 then
dbms_output.put_line('------ int[134217724] hit ORA-29532: java.lang.OutOfMemoryError ------');
l_es_ret := dbms_java.endsession;
p_define_int_array(134217723);
dbms_output.put_line('------ int[134217723] Succeed ------');
when others then
raise;
end;
/
Exception in thread "Root Thread" java.lang.OutOfMemoryError
at Demo.defineIntArray(Demo:5)
------ int[134217724] hit ORA-29532: java.lang.OutOfMemoryError ------
OracleJvm int[].length: 134217723
------ int[134217723] Succeed ------
set serveroutput on size 50000;
exec dbms_java.set_output(50000);
declare
java_oom_27102 exception;
pragma exception_init(java_oom_27102, -27102);
l_es_ret varchar2(100);
begin
createBuffer512_loop(511, 1, 1);
exception
when java_oom_27102 then
dbms_output.put_line('------ createBuffer512_loop hit ORA-27102: out of memory ------');
l_es_ret := dbms_java.endsession;
createBuffer512_loop(3, 1, 1);
dbms_output.put_line('------ createBuffer512_loop(3, 1, 1) Succeed ------');
when others then
raise;
end;
/
Step -- 284 --, Buffer Size (MB) = 284
Step -- 285 --, Buffer Size (MB) = 285
------ createBuffer512_loop hit ORA-27102: out of memory ------
Step -- 1 --, Buffer Size (MB) = 1
Step -- 2 --, Buffer Size (MB) = 2
Step -- 3 --, Buffer Size (MB) = 3
------ createBuffer512_loop(3, 1, 1) Succeed ------