Assert Warning: Memory block header corruption detected in mt_realloc 2

Hi, IBM Informix Dynamic Server Version 11.70.FC5XE We got the following warnings: 17:58:53 Assert Warning: Memory block header corruption detected in mt_realloc 2 17:58:53 IBM Informix Dynamic Server Version 11.70.FC5XE 17:58:53 Who: Session(5284871, sap_xi@pfp-app1, 0, 70000423f9c9f08) Thread(58573054, sqlexec, 70000449bf0d068, 13) File: mtshpool.c Line: 2988 17:58:53 Results: 17:58:53 Action: Please notify IBM Informix Technical Support. 17:58:53 stack trace for pid 13697538 written to /tmp/af.c4e6ed2d /tmp/af.c4e6ed2d is as follows: 17:58:53 Found during mt_realloc 2 17:58:53 Pool 'EXE.5284871' (0x700004f954b7040) 17:58:53 Bad block header 0x700004bcb9f0028 blk-640700004bcb9effe8: 3422206c 696e655f 6e756d3d 22313030 4" line_ num="100 0700004bcb9efff8: 22206974 656d5f6e 756d3d22 35303731 " item_n um="5071 0700004bcb9f0008: 38222071 74793d22 31302220 69735f64 8" qty=" 10" is_d 0700004bcb9f0018: 616d6167 653d2222 2f3e0a3c 6c696e65 amage="" />.<line blk+64 0700004bcb9f0028: 0000009b 60ea6081 ffff04e0 008008c1 ....`.`. ........ 0700004bcb9f0038: 0700004f 954b70a8 0700004b cb9ee000 ...O.Kp. ...K.... 0700004bcb9f0048: 00000000 00000fd8 0700004f 954b70e8 ........ ...O.Kp. 0700004bcb9f0058: 0700004f 954b70e8 0e00009f 2a96e1d1 ...O.Kp. ....*... 17:58:53 Bad block removed from pool 17:58:53 Attempting to clean up free list... 17:58:53 Bad free block 0x700004bcb9f0050 blk-640700004bcb9f0010: 31302220 69735f64 616d6167 653d2222 10" is_d amage="" 0700004bcb9f0020: 2f3e0a3c 6c696e65 0000009b 60ea6081 />.<line ....`.`. 0700004bcb9f0030: ffff04e0 008008c1 0700004f 954b70a8 ........ ...O.Kp. 0700004bcb9f0040: 0700004b cb9ee000 00000000 00000fd8 ...K.... ........ blk+64 0700004bcb9f0050: 0700004f 954b70e8 0700004f 954b70e8 ...O.Kp. ...O.Kp. 0700004bcb9f0060: 0e00009f 2a96e1d1 0700004b cb9f00b0 ....*... ...K.... 0700004bcb9f0070: 0700004b cb9f00f0 00000000 00000000 ...K.... ........ 0700004bcb9f0080: 00000000 00000000 0e00009b 60ea8049 ........ ....`..I 17:58:53 Bad free block removed from pool 17:58:53 17:58:53 IBM Informix Dynamic Server Version 11.70.FC5XE Software Serial Number AAA#B000000 17:58:53 Assert Warning: Memory block header corruption detected in mt_realloc 2 17:58:53 Who: Session(5284871, sap_xi@pfp-app1, 0, 70000423f9c9f08) Thread(58573054, sqlexec, 70000449bf0d068, 13) File: mtshpool.c Line: 2988 17:58:53 Results: 17:58:53 Action: Please notify IBM Informix Technical Support. 17:58:53 Raw hex dump of stack located in /tmp/af.c4e6ed2d.rawstk 17:58:53 Stack for thread: 58573054 sqlexecbase: 0x0700004410659000 len: 135168 pc: 0x0000000100096cec tos: 0x0700004410675800 state: running vp: 13 0x0000000100096a98 (oninit)afstack 0x000000010009603c (oninit)afhandler 0x00000001000963ec (oninit)afwarn_interface 0x0000000100068294 (oninit)mt_realloc 0x00000001001d4ee8 (oninit)mi_realloc 0x0000000100556fe4 (oninit)genxml 0x000000010055fc50 (oninit)iter_aggrxmlc 0x0000000100dddb1c (oninit)udrlm_clang_execute_internal 0x0000000100ddd728 (oninit)udrlm_clang_execute 0x00000001013c5550 (oninit)udrlm_exec_routine 0x000000010061c72c (oninit)udr_execute 0x00000001005507b0 (oninit)sqexop 0x00000001013a0320 (oninit)compagg 0x000000010139ef70 (oninit)updategrpcols 0x000000010139bb88 (oninit)process_non_groupby 0x0000000101398e54 (oninit)group_open 0x000000010068c460 (oninit)prepselect 0x00000001002ca0d0 (oninit)subqprep 0x00000001002c8fe8 (oninit)exsubq 0x000000010083d868 (oninit)ev_cb 0x0000000100833c10 (oninit)new_eval 0x000000010069f548 (oninit)IPRA.$ip_evalexpr 0x000000010069caec (oninit)runproc 0x00000001006b1dfc (oninit)udrlm_spl_execute 0x00000001013c5508 (oninit)udrlm_exec_routine 0x000000010061c72c (oninit)udr_execute 0x00000001006adeb4 (oninit)udr_spl_curnext 0x00000001006adb04 (oninit)ip_curnext 0x00000001006add50 (oninit)ip_fetch 0x0000000100689754 (oninit)getrow 0x000000010068acd8 (oninit)fetchrow 0x0000000100737b44 (oninit)exfetch 0x00000001001fb024 (oninit)sql_nfetch 0x00000001001fa808 (oninit)sq_nfetch 0x00000001004889c0 (oninit)sqmain 0x00000001009f8cd4 (oninit)listen_verify 0x00000001009f7d88 (oninit)spawn_thread 0x0000000101489440 (oninit)startup 17:58:53 See Also: /tmp/af.c4e6ed2d ------------------------------Begin System Alarm Program Output ------------------------------ Assertion Failure Type: Warning Host Name: elids5 Database Server Name: elids5 Time of failure: Fri Mar 1 17:58:53 MSK 2024 AF file: /tmp/af.c4e6ed2d Shared memory file: None System Blocking: OFF ------------------------------ End System Alarm Program Output ------------------------------ 17:58:53 sh /opt/informix/11.70fc5xe/etc/evidence.sh 1 0 /tmp/af.c4e6ed2d 5284871 0x70000449bf0d068 58573054 0x700005161e61220 1025 0 0 0 0 17:58:53 ------------------ End of assertion failure 0 ---------------- -A failing query that causes the warning is: SELECT genxml(row(line_id, line_num, item_num, qty, is_damage, is_cross_docking, mark_chz),"line") <...> Does genxml() have any tips and tricks to tune? ------------------------------ Sincerely, Dennis ------------------------------

Just a memory issue, if it is repeatable I would separate into separate SQLs (if possible). You are not going to get IBM to fix this, but might be a known stack Cheers Paul

An idsxmlvp virtual processor is declared to be created automatically the first time an XML function is used. However, there is no idsxmlvp VP running. Is it optional? Should I add the VP manually? ------------------------------ Sincerely, Dennis ------------------------------

If the VP is mandatory then you should get an error indicating that if it can't be found.

Digging deeper into the problem we found that the query fails with error -8369, -8369 Function <funcname> Memory allocation for internal buffer failed Explanation:Function <funcname> was not able to allocate more memory. Action:Make sure that the system has enough memory to run the command. If the problem persists, contact Technical Support to resolve the problem. The failing set has 125 rows. At the same time, another set of 335 rows is handled by genxml() without a problem. Q: How to tune the internal buffer, how to check it has enough memory? Can the problem be related to RSS replication? ------------------------------ Sincerely, Dennis ------------------------------

Our further investigation proved we have encountered an apparent Informix's bug, i.e. the AF is triggered by the order rows lie in the set--the query succeeds if the order is reversed. ------------------------------ Sincerely, Dennis ------------------------------

Provided a reproduction, this could be tried with a recent Informix version. ------------------------------ Andreas Legner ------------------------------

Andreas, To reproduce, CREATE TEMP TABLE tmp_osa5632 ( line_id INTEGER, line_num INTEGER, item_num CHAR(10), qty CHAR(10), is_damage CHAR(1), is_cross_docking SMALLINT, mark_chz CHAR(1) ) WITH NO LOG; LOAD FROM 'osa-5632.unl' DELIMITER "|" INSERT INTO tmp_osa5632;SELECT genxmlclob(row(line_id, line_num, item_num, qty, is_damage, is_cross_docking, mark_chz),"line") FROM (SELECT line_id, line_num, TRIM(item_num) AS item_num, TRIM(qty) AS qty, TRIM(is_damage) AS is_damage, is_cross_docking, mark_chz FROM tmp_osa5632 ORDER BY line_id); First, save it to 'osa-5632.unl': 865147945|1|256112|10|\\ ||| 865147946|2|856689|11|\\ ||| 865147947|3|1021606|41|\\ ||| 865147948|4|1061718|50|\\ ||| 865147949|5|1495398|57|\\ ||| 865147950|6|1495408|64|\\ ||| 865147951|7|1613576|2|\\ ||| 865147952|8|933324|52|\\ ||| 865147953|9|933325|43|\\ ||| 865147954|10|933327|41|\\ ||| 865147955|11|933329|59|\\ ||| 865147956|12|1258553|229|\\ ||| 865147957|13|877410|33|\\ ||| 865147958|14|26917|4|\\ ||| 865147959|15|1472044|3|\\ ||| 865147960|16|1079352|104|\\ ||| 865147961|17|1195820|4|\\ ||| 865147962|18|762|89|\\ ||| 865147963|19|882896|77|\\ ||| 865147964|20|517148|5|\\ ||| 865147965|21|328755|9|\\ ||| 865147966|22|964109|6|\\ ||| 865147967|23|964108|6|\\ ||| 865147968|24|964107|6|\\ ||| 865147969|25|964106|13|\\ ||| 865147970|26|867261|30|\\ ||| 865147971|27|867249|127|\\ ||| 865147972|28|166832|1|\\ ||| 865147973|29|1136178|116|\\ ||| 865147974|30|147841|18|\\ ||| 865147975|31|882894|101|\\ ||| 865147976|32|262865|34|\\ ||| 865147977|33|198685|22|\\ ||| 865147978|34|129|46|\\ ||| 865147979|35|1547354|109|\\ ||| 865147980|36|112336|6|\\ ||| 865147981|37|1111999|10|\\ ||| 865147982|38|1442|7|\\ ||| 865147983|39|901708|166|\\ ||| 865147984|40|901702|31|\\ ||| 865147985|41|901704|5|\\ ||| 865147986|42|1113840|9|\\ ||| 865147987|43|737053|12|\\ ||| 865147988|44|1348206|7|\\ ||| 865147989|45|906433|81|\\ ||| 865147990|46|900306|79|\\ ||| 865147991|47|1384140|123|\\ ||| 865147992|48|809697|12|\\ ||| 865147993|49|274113|35|\\ ||| 865147994|50|916920|40|\\ ||| 865147995|51|891642|44|\\ ||| 865147996|52|115676|15|\\ ||| 865147997|53|1153854|4|\\ ||| 865147998|54|127651|30|\\ ||| 865147999|55|1467018|111|\\ ||| 865148000|56|882891|1|\\ ||| 865148001|57|257232|17|\\ ||| 865148002|58|76130|30|\\ ||| 865148003|59|129819|119|\\ ||| 865148004|60|1556510|44|\\ ||| 865148005|61|949924|2|\\ ||| 865148006|62|201928|13|\\ ||| 865148007|63|396998|2|\\ ||| 865148008|64|650136|5|\\ ||| 865148009|65|979412|14|\\ ||| 865148010|66|979413|14|\\ ||| 865148011|67|144630|60|\\ ||| 865148012|68|1277748|21|\\ ||| 865148013|69|730859|14|\\ ||| 865148014|70|730858|6|\\ ||| 865148015|71|266552|29|\\ ||| 865148016|72|27258|10|\\ ||| 865148017|73|1121495|7|\\ ||| 865148018|74|52638|25|\\ ||| 865148019|75|1202371|11|\\ ||| 865148020|76|1226617|7|\\ ||| 865148021|77|892707|26|\\ ||| 865148022|78|633901|117|\\ ||| 865148023|79|954118|51|\\ ||| 865148024|80|916459|51|\\ ||| 865148025|81|916461|18|\\ ||| 865148026|82|916460|11|\\ ||| 865148027|83|1471178|7|\\ ||| 865148028|84|10018|1|\\ ||| 865148029|85|710171|39|\\ ||| 865148030|86|47585|66|\\ ||| 865148031|87|1479872|12|\\ ||| 865148032|88|76335|1|\\ ||| 865148033|89|926648|15|\\ ||| 865148034|90|33177|28|\\ ||| 865148035|91|1243049|28|\\ ||| 865148036|92|1203507|36|\\ ||| 865148037|93|1547365|44|\\ ||| 865148038|94|1547364|44|\\ ||| 865148039|95|34468|17|\\ ||| 865148040|96|254660|2|\\ ||| 865148041|97|1647993|2|\\ ||| 865148042|98|901703|112|\\ ||| 865148043|99|919791|33|\\ ||| 865148044|100|50718|10|\\ ||| 865148045|101|434191|415|\\ ||| 865148046|102|934504|1|\\ ||| 865148047|103|1742607|4|\\ ||| 865148048|104|148250|50|\\ ||| 865148049|105|1252582|17|\\ ||| 865148050|106|146162|11|\\ ||| 865148051|107|491330|268|\\ ||| 865148052|108|263350|70|\\ ||| 865148053|109|107250|27|\\ ||| 865148054|110|198|15|\\ ||| 865148055|111|601885|3|\\ ||| 865148056|112|253736|29|\\ ||| 865148057|113|392958|10|\\ ||| 865148058|114|73647|2|\\ ||| 865148059|115|965722|50|\\ ||| 865148060|116|19757|30|\\ ||| 865148061|117|33055|3|\\ ||| 865148062|118|1675999|13|\\ ||| 865148063|119|257241|22|\\ ||| 865148064|120|347861|9|\\ ||| 865148065|121|917380|36|\\ ||| 865148066|122|901705|4|\\ ||| 865148067|123|1752211|1|\\ ||| 865148068|124|874769|10|\\ ||| 865148069|125|1593980|4|\\ ||| ------------------------------ Sincerely, Dennis ------------------------------

INFORMIX 14.10.FC10 on Ubuntu 22.04: No Problem. I get the XML and at the end: 1 row(s) retrieved. Mit freundlichen Grüßen - Kind regards Gerd Kaluzinski Consultant Software Services IBM Expert Labs DACH, Data & AI Phone: +49 175 228 1983 EMail: gerd.kaluzinski@de.ibm.com IBM Deutschland GmbH Vorsitzender des Aufsichtsrats: Sebastian Krause Geschäftsführung: Gregor Pillen (Vorsitzender), Nicole Reimer, Gabriele Schwarenthorer, Christine Rupp, Frank Theisen Sitz der Gesellschaft: Ehningen / Registergericht: Amtsgericht Stuttgart, HRB 14562 / WEEE-Reg.-Nr. DE 99369940